i installed a manuel transmission in my 89' rx7 and i noticed i can only get it to go into first and second gear, i havent started the car yet and tried to drive it because i still need to buy starter but i was wondering if the problem will correct itself once i try to drive it or if something is wrong.

 

Tranny might be broken. Hopefully theres no internal rust or binding.
But, most likely its just 'dry'. Once its moving again, gear oil will splash everywhere and make shifting possible.