I run a Focusrite into Ableton....and firstly your questions are not dumb....it was an nightmare for me as it wasn't a simple plug and play.
I'll start with the statement that 90% of the setup is windows playing nicely with Focusrite. Ableton doesn't need much set up.
I can;t remember exactly what I did but from memory:
- Defo run with ASIO. I think I may have had to install ASIOFORALL ( someone else comment please)
- You need to manage the Focusrite settings in Mixcontrol which should have been installed ( I run an 18i8)- The issue I had was not no sound but ghost sound...but my point is I played with monitoring settings and buffer size.
- Focus on just getting an unprocessed sound i.e. take the KPA out of the equation for now and just get your bass coming out in Ableton. BTW You need to "arm" a track ( ready to record) and set to auto monitor.
Hope that helps in some way although I'm a very basic user.