My truck is a 1984 toyota 4x4 and it has been wheeled to the extreme and rolled and been through hell and back but everytime I go to press on the brakes the truck wants to pull to the right. My dad says I have to adjust the brakes but I dont know how to do that.
Firstly you need to make sure the brakes are all in good condition. Are they discs or drums? If they are drums, are they manually adjustable or automatic?
Pulling to the right usually means the ones on the left aren't working properly, but if you do anything to them you need to do the same to both sides - otherwise you'll just find it pulls left instead!
Unfortunately, being a 4x4, you can't put it on a brake tester, but you can get a reasonable idea - jack the truck up and support it on axle stands. Turn each wheel and see how they feel - both sides should spin freely. Then get an assistant to press the brake pedal and try again - you shouldn't be able to spin them by hand.
Check the flexi hoses, and if in doubt, replace them. If it's discs, check the condition of the calipers, check that the sliders slide freely, and check or replace discs and pads. If it's drums, check or replace the cylinders and shoes, and clean up and check the adjuster mechanisms and springs.
Brakes are the most important thing on your vehicle, so if in doubt, consult a professional.