[JeffeFawkes]

Check out Korg Gadget![0] It's got an Ableton-Live-style clip launcher that's easy to compose in, and a variety of "gadget" instruments that produce different kinds of sounds. If you balk at $30 for an app, it goes on sale for half price a good 3-4 times a year, usually around holidays. You can hook up any midi devices (BLE midi or via the USB camera kit adapter, if not on a usbc iPad). If you've got an iPad with a headphone jack you can pick up an iRig clone for <$10 that gets you line / mic / guitar input, too.

If you've got an iPad that's probably the best start (it'll run on any iPad 2 or above). It will run on iPhone's but it's a bit harder to play. There's also a Nintendo Switch version (it's more limited, eg no audio recording or export), and a mac version (but it's pricey). Annoyingly, the Mac and iOS versions are separate, but at least the iPhone and iPad versions come together as one purchase.

[0]: https://www.korg.com/us/products/software/korg_gadget/