Reaper | Oops
Pop pop pop!
Making mistakes is inevitable. There are many ways to fix your mistakes with audio software but I like this one because you don't have to re-record.
You make a mistake, you say, rather forcefully (and loudly) "Pop Pop Pop!" and then you start again where you messed up. Watch the video, you'll see what I mean.
Then, you go back, look for the 3 peaks, delete where you messed up, and stitch the two good parts together. Easy peavey.