Dont need trade plates unless it has no tax as i took a new VW Golf out for test drive with tax and no traders plates..
For a start you picked a bad choice of car to start track driving imo.. But as you have it and have pulled it to pieces..
Roll cage ( full not a fanny half cage )
Big brakes ( or good quality disks and pads
Move battery to boot
remove air con and all associated parts..
relocate washer bottle to boot..
change bonnet and wings for carbon/ fiber glass copies..
lower on coilovers of good quality and dampening adjustable
carbon fibre bucket seats
and proper harnesses
a decent full exhaust manifold back
air filter with cold air feed..
get it rolling roaded and set up properly
front splitter
good quality helment and race suit ( as you dont want to burn in a fire lol )
maybe race logic traction control
The list my friend is endless with out a budget and without knowing what you really want to do no advice can be given..
And please please please please don't write a thread in capitals is very f**king annoying

All the best
tech1889