Replying to Car question (oil change related)

So im pretty tight for money right now. I need an oil change for car (2003 vw jetta). Now an oil change around where i live is going to run about 45 bucks. My question to the NS car people is, can i just buy some oil and pour it into the oil area in the engine. Idk if this is a solution or should i just get a normal oil change. I know its a pretty noob question i don't want hate. I dont know how to do oil changes myself. Buying a quart of oil will save me enough for gas for another week. But i feel like that pouring oil into the thing isn't going to really help anything