I am looking for a laptop and I need one that doesn't cost more then 300$ but I don't know much of anything about them and I would apreciate some help thanks!
I would not recommend that used laptops since it has a very weak APU; low processing power and graphics performance.
The following new 15.6" HP laptop for $250 is your best option. It has an AMD A8-6410 APU which is more powerful than the APU in the above linked laptop. It is really the best option so buy it before the Mother's Day sale ends.