I think you are overthinking this. If you can figure out Audacity, you can figure out Reaper 
Try the free trial of Reaper and watch some of Kenny Gioia’s excellent instructional videos - give it a shot!
otherwise, what came with your DAI? Most include licences for the entry level versions of pro DAWs - things like Pro Tools First, Ableton Live Lite, etc.
Next one I would call out is CakeWalk.
But really, just try Reaper. It’s not really difficult to get started than Audacity, just far more capable.