i just got a toyota corolla 91'.  what should i first get for the car?  

First off, the engine isn't that strong in that model. It's all of, what, 98hp? If you plan on spending some money on it and want some cojones, don't think that it's going to be cheap. An engine swap is in order if you really want to see a difference on hp. Next, even if you get that particular swap you still may need to refresh it. I.E., new seals, maybe check for internal damage of any kind through a machine shop, replace internals if it's a high mileage swap you got. That also requires a new oil pump, water pump... That's just basic stuff so that it doesn't leave you walking, inexplicably. After that the list gets longer because the swap isn't plug and play. You'll need the PCM, wire harnesses with connector kits, just in case you need to splice or make a connector, better fuel delivery system and better intake and exhaust system... The list is not over but you get the idea. Swaps are cool but you have to know what you're getting into before you dive in. It's a good little car as it is. Fuel economy isn't like the newer models but still good. To phrase a good guy, Start with brake upgrades and wheels and a good exhaust, and maybe a good cold air intake. The intake and exhaust upgrades is good for a good 2 to 5 horses. If you want more you have to pay the performance piper. LOL! And ever thing will be just about custom, too. Good luck.