Another cheap (free) option is Audacity. That is pretty simple to use but more limited than Reaper. I downloaded Reaper this week and it’s taken quite a while to work out overdubbing, whereas in Audacity it seems to be more intuitive. I’ll buy the Reaper license and stick with it as it’s far more versatile but if I didn’t have any previous experience (very old version of Soundforge and Audacity) I wouldn’t know where to begin. This lady may become your new best friend, she explains stuff really well:
Music Reapo