Due to your age I would get a few insurance quotes first, some younger people have been known to insure cars with undeclared mods, and had thier car scrapped due to the insurance being null and void.
You will probablt be best just putting in for the mot, but it's going to have rusty discs, need a oil/filter change, and unless belt is new need that as well just to be safe.
Once it's been to mot, just do whatever it finds, if anything, and give it a full service with above bits plus fuel filter, then you would be best next getting it on the rolling road for a fuel check out.
tabetha