My plastation 2 slim won't play ps1 games and even dvd's. Please help! :(?

Can your PS2 play PS2 games? Because those are DVDs. Try cleaning the disc or wiping down the disc bay. The simple stuff works sometimes. If the disc looks overly scratched, take it to gamestop and trade it in. They will pay you and whatever it costs to fix the disc($0.75-$2) will come out of the trade money. Buy a new one with the rest of the money.