Driving

I didn't grow up in Northern Ireland, and don't really have anyone to ask these things but can someone help me understand getting driving? I am a late starter with driving due to extreme anxiety around it but really want to get going.

Do I apply for a provisional licence then take a theory test and then do my lessons and test?

What's the best way to study for the theory test? Is there an app or mock test website that's reliable?

Also, general cost idea would be great.