I have audiobox2 with a mic and the line out of a E Piano connected. tablets are iPad 6th and 7th gen. both AudioBox Ione and iTwo would run w/ GarageBand. My e - piano has also its own audio interface integrated, ( usb audio , midi) , I can connect it directly ( camera connector) to the iPad, but: either connect the usb of the E- Piano, or the I-two.
I One: Input1 : Microphone XLR, 48V optional. Input2: Instrument, e.g. E Guitar.
I Two: two Inputs Microfone XLR / Line, Instrument Jack Plug combined. Plus MIDI In Out on the rear. (standard 5 pin plugs). It‘s more versatile.
If you want to use more than two microphones, you need other devices.
The DAW from Presonus for the iPad Capture Duo (2 tracks, upgradable to 32 tracks) is a simple one. You have to transfer ( WLAN) the results to Studio One 5 Artist Edt. ( Apple OS or MS Windows) to work with VSTs etc. Both software is included when buying the hardware.