Advice to use a Mac Mini without display, but using an iPad (sidecar / screen sharing / remote desktop?)
What you want to do is entirely possible (in fact, it's pretty close to what I do).  There are a few things to be aware of.


For initial set up you will need to connect your MacMini to a monitor, keyboard and mouse.  Once you've set it up you can hide it away (provided that you have a good flow of air for cooling) and connect from your iPad.
Due to some oddity in macOS or in the Mac Mini yourself, you won't get full performance in this configuration.  To get full performance you will need to connect a dongle to your Mac's monitor port to make it think that it has a monitor connected.  Weird, no?  But it works.  Something like this. https://www.amazon.co.uk/s?k=CompuLab+Display+Emulator&amp;ref=nb_sb_noss


Enjoy.