It doesn’t really matter if you know his birthday, by spending time together. You will get to know what he is really like 👍

But im not like that close with him,idk his birthday and that kinda stuff

Hey, it sounds like it might be a good idea to actually spend some time with him face to face in order to see if you like him or not. Maybe arrange a fun day out with you and him, or if that feels too overwhelming, then get 2 or 3 people to join. The point would be to spend time directly with him to see how you feel and to see if he feels something for you too.