I’m trying to use the Genki listening exercises to practice speaking aloud and shadowing. However, I find that using Audacity is a pain because you can’t quickly edit a mistake you made - you have to add a new track and copy and paste it in, etc etc. It really slows down my workflow.
How did you guys practice shadowing and recording?
Windows has a voice recorder app if that works
EDIT Oh you want to be able to edit Genki’s recordings?
I’ve only had experience with Fruity Loops as a music program, I can’t say it’s intuitive, though. (nor cheap unless your uni’s paying for it)
I’m afraid I can’t help in that regard, but best of luck finding a good method!
ORIGINAL
Echo app (https://play.google.com/store/apps/details?id=uk.co.projectneon.echo)
)You can also save the recordings, naturally 
The main benefit for me is ease of use; as soon as I let go I can immediately hear myself back, which makes it easier to use thus makes me use it more!
Am I understanding correctly that you want to edit things like… for instance if you said あした がこう に いきます, instead of あした がっこう に いきます, you would want to snip out がこう and replace it with がっこう? Why not just re-record the whole sentence?
I do want to re-record the whole sentence, but the genki recordings make you say one sentence after another, so I end up with ~15 sentences in a row. I just want to fix 1 sentence at a time instead of re-recording all 15 sentences.
Maybe use Garageband, it’s free. A lot of audio editors have punch-in recording. So it only records when you punch in for a segment of the audio (You set the start and end point of the punch in and punch out so no other audio gets affected). I’m not 100% if I understand your needs but that may be the feature you’re looking for in whatever audio editor you use.
Some editors also have looped-take recording where you can setup a loop segment and record yourself multiple times doing the same segment and then choose the best take at the end, or combine takes.
Unfortunately I don’t have a mac 
I see. I think you can run Garageband on windows using VMWare. I think theres many free ways to run other operating systems on your current operating system.
But the easiest thing would be to get a free windows audio editor. Maybe see if audacity has punch-in or loop recording before considering switching to another program.
EDIT: I just googled it. Apparently Audacity is capable of both punch-in recording and loop recording so you should be all good. Watch some youtube tutorials to see how it works.