I think my dad found some info? Helpp?

If you use the same computer all your info stays on it. All he had to do was search the history and saved passwords. You don't state your age, but if youre over 16 its a little rude for him to spy and just not ask you about things..and immature as well. He WANTS to catch you doing things because it makes him feel more in control. That being said, if you're 12- 15 he's still be childish but has more of a right.