It looks like you need to learn how to record... So it is not a question of recording a Kemper or not. learn to record anything, voices keyboard guitar bass drum loops midi etc...
So download a Cubase TRIAL FOR FREE and study how to record. Go to a Cubase Forum too
Good luck
Google 'guitar interface for mac', and there is a lot of choice. Yes, you need an interface to record 'anything' on your mac. Many brands of software available, Logic Pro (my choice), Reaper, Cubase, Pro Tools, Ableton etc.
Reaper is a good and cheap option. You need some interface obviously. The soundcard in your computer may do the job, but a good external interface that has analogue and Spdif inputs will be way better. If you are going to record vocals etc you will need much more. A decent mike in the first place. The interface may have a decent preamp but you will see that the best interfaces are not cheap. It all depends on what your aims are. If you are using backing tracks or midi synths it's easier, but recording bass, drums etc... And you'll need time, patience and advice from somebody with more experience if possible. Good luck.
I’m wanting to start recording guitar with the KPA but am very much a noob.
What is your budget? How are you going to use it?
You're on Mac, so the obvious, cheapest, easiest-to-use app is... Garage Band.
My brother's a PC guy, but he bought a Mac laptop specifically so he could run GB as he reckons nothing else came close to its ease of use.
You're on Mac, so the obvious, cheapest, easiest-to-use app is... Garage Band.
My brother's a PC guy, but he bought a Mac laptop specifically so he could run GB as he reckons nothing else came close to its ease of use.
And if you like GB and find you outgrow it you can upgrade to Logic Pro which has a very similar user interface. I use Logic and love it. I could use another DAW like Cubase, Repaer or ProTools but they all do essentially the same thing. The main differences are in user interface so I don’t feel any great desire to relearn a whole new system.
As others have said you will need an audio interface. There are too many to choose from to even start discussing but you can’t go wrong with something like the like Focurite stuff.
You're on Mac, so the obvious, cheapest, easiest-to-use app is... Garage Band.
My brother's a PC guy, but he bought a Mac laptop specifically so he could run GB as he reckons nothing else came close to its ease of use.
+1 on Garage Band as you already have it.
Yes an interface is needed. If you learn reaper, it can work any way you want. Just crazy amazing for the price, plus it never crashes (at least for me coming from Sonar)
I started with a Scarlet 2i2 and Reaper. Reaper is great because you can download and install a full functioning version and try before you buy - honor system. They have a user forum too. I honestly had a hard time with garage band utilizing my drum machine software and that drove me to Reaper.
Honestly, I had a hard time with the drum machine software too. 
Reaper was the easiest out of it all to learn in terms of the base functionality, but I only use it for laying down ideas, and never did any real production with it.
I started with a Scarlet 2i2 and Reaper. Reaper is great because you can download and install a full functioning version and try before you buy - honor system. They have a user forum too. I honestly had a hard time with garage band utilizing my drum machine software and that drove me to Reaper.
Honestly, I had a hard time with the drum machine software too.
Reaper was the easiest out of it all to learn in terms of the base functionality, but I only use it for laying down ideas, and never did any real production with it.
Yes, I think that Garageband may be more limiting in the long run. I started on a very simple 'DAW-Lite" program, and stuck with it for years because it was easy and worked for demos for my bandmates to work off of. I am just now learning the ins and outs of a real DAW, and I wish I had done it a long time before. Garageband is a great user friendly surprisingly powerful recording tool, but Reaper is the real deal, it'll do whatever you need.
A Focusrite is your best option IMHO. As @flyingheelhook mentioned, it's a good starter! 
Reaper for $60 bones is awesome, but the evaluation copy will work for 60 days until you are ready to pull the trigger and purchase it. A few years ago I remember having it for over the 60 day mark as I wasn't quite sure if I wanted to make the jump from Pro Tools. I'm not sure if they still allow that? I got it anyways, for my laptop lol. Reaper is super flexible! 
I use a Universal Audio Apollo 8 with Pro Tools 12. This works well, for me, but it wasn't exactly cheap. Especially when you factor in buying plugins, bundles and various programs. 
Be sure to use SPDIF connectivity if you check a new sound card
and yes I would recommend using simple tools like garage band , that will allow you to focus on playing & recording music instead of learning from scratch a new very complete DAW like reaper ( I use it for mixing myself , but not for writing ).
I you're noodling and find great ideas, you'd just have to load your software and hit record, then you' ll not loose a great feel and flow. Nothing worse that setting up levels, adding a new track , setup beat ... When you're done, you've lost most of your motivation & creativity.
I often use my phone recorder to store ideas at night or even in the morning , just waking up with a melody in my head, I then hum , whistle or sing it to my phone ... it's stored for later usage and real production.
Be sure to use SPDIF connectivity if you check a new sound card
Just a quick note: The Scarlet 2i2 does NOT offer SPDIF and anyone looking to pursue recording should probably factor that into whatever decision they make regarding an audio interface.
Reaper for $60 bones is awesome, but the evaluation copy will work for 60 days until you are ready to pull the trigger and purchase it.
I believe you can still use the legit full featured "free trial version" of Reaper after the 60 days (for ever). You used to just close the single popup that opens when program launches, and you're off to the races. Was more of a laid back prompt than a demand Would love to know if this is still the case?
As far as software goes, IMO Reaper is the bomb for recording. Have multiple other DAWs but Reaper is the one I recommend. Its crazy small to download (less than 20mb currently), super super stable, easily skinable to both look and act much like any other DAW (why have one when you can basically have them all?), well suppoted (several updates a year with new features people have requested - much like our Kemper coding friends!) and imo, easier to instantly use (in default config) than most "studio" Daw's. As easy to get pro results on Reaper as any other DAW as all of them are basically just a user interface to manipulate audio files. Oh, it can do video too with a simple download.
I paid for Protools a few years back (spendy!) to prep tracks with the inbuilt plugins as almost all studios were using that exclusively at the time, and it was fine to record and interact with, but nowdays I don't even load it. The old squillion dollar PT iLok just sits in a drawer currently.
Really, imo Reapers only weakness is the lack of super fancy onboard plugins, and this can be an issue for many, but all the basics are included and a great way to learn what settings actually do with out just mashing through pretty skinned presets (oh, plugins and vsts are like Kpa profiles btw. Collecting them can become stupidly addictive. Fun to tinker with, but can quickly kill your productivity )
All that said.. if you have Garage Band, give that a spin for sure. Have friend who do demos on that and its seems very 7ser friendly. Recording is super accesable nowdays and a cool adventure to get into.
Hit record, and play. You can't lose.
oh. and another +1 for the Focusrite Scarlett. Get the one with the amount of channels you will actually use, and go for it.
