Hey! I have the same..
For any new project, I always start with: Brakes/Rotors, Wheels, Oil, Battery
For the Celica, specifically: Spark Plugs, Lift Bolts, Headunit, Sunroof (Glass or Plastic), Interior Lights, Rear Hatch Struts
Mod Wise: Coilovers/Lowering Springs, Upgraded Camber Arms, maybe bigger tyres
Cosmetic: Front Bumper Mesh, Headlights/Taillights, Spoilers