Earlier quoted context omitted.
You can _definitely_ learn enough garage band to make a simple loop! It's very easy to set up, actually - at least on desktop, and I'm sure it's similar enough on the mobile app. You can mark a section on the timeline to loop, and if you record when you're in that state, it'll just continually record to that same section of track. You can also set it up to do a metronome count in before actually recording. So, if you…
I upvoted your comment earlier but I figure thanking you explicitly for that advice would be more courteous. So, thanks!
You're welcome! Hope you have fun.