Best way to load and play multiple audio files(looping, synchronised)?

For my dissertation I’m writing an Android App for beginner producers that uses 20 toggle on/off loops. I have most of the UI, but I just got the code working so that I can load a file from a fileChooser and play it.
The goal: loops that are toggled on play, loops that are toggled off don’t.

My question: What’s the best(efficient) way to load 20 audio loops(9 sec wavs), play about 8-10 loops of audio at once, and have them start at the same time(to the same clock). I’ve currently got the loops exported as wav files, but can do mp3 as well.
This needs to be optimal because the target platform is Android - if the final latency is acceptable.

Loading them (into memory?) without a filechooser is also confusing to me: what happens when I export this to an APK, how do I package them so that I don’t have to rewrite code once I load all the loops? It would also be useful to be able to “point” to a directory and have 20 loops in there automatically loaded and linked to the buttons.

I’m new to JUCE and C++ so:
Thank you so much!!!