A 90 with a 5spd for $1000? sounds like you got a great deal! Supra's are alot of fun to own and IMHO one of the sexiest sports cars, period...much less one you can get for around a grand.
Make yourself a bookmark to the TSRM :
http://www.cygnusx1.net/supra/library/TSRM/ or DL this one:
http://groundsky.co.nz/techinfo/TSRM/
...and start reading threads here about the stuff you want to do. Please do your research before asking a question though, as you will find most questions have already been asked and discussed at length.
Enjoy owning a special car, owned by special people.....Just ask Supra2NR if hes special, but please wait until he exits the short bus.