So the guy I like, we started talking about being more than friends. He told me he would want to go out with me, I told him I would like to go out with him. But he is worried it will ruin our friendship... We have so many things in common we get along really good, and like to hangout and have fun. But he is still worried about our friendship, I'm not sure what to do now... Should we stay friends or should we try the relationship thing.

The old it will ruine our friendship saying.

Ok two things here

1 it already has changed your friendship because both of you have spoken about your feelings. Now comes the are you both willing to move forward he seems a bit scared, now my view is the best relationships are formed from that first friendship

Talk to him and tell him let's just take it slow and see what happens.
But only talk about it once you don't want to beg someone for affection

So that's it your frienship has already changed because you feel different about him and if nothing happens could you. Really see him going off with another girl then coming home and telling you how it went?
Umm no


So have a real talk with him.

2nd thing my advice if it does not go well if you are strong enough to stay friends with him without jealousy or anything like that
Which I doubt not many people are
The be friends with him

My advice would be to loosen the friendship a bit and back off
Only to protect yourself

All the best
So it's out in the open have a real grown up talk with him. Tell him how it has changed the friendship and see where it goes from there

https://www.askmehelpdesk.com/teens/how-do-get-guy-boyfriend-595430.html

Same guy? Would help to know your ages, but when a guy has second thought, or not sure, or is INEXPERIENCED, then that would be a sign not to push. That's why ages are so important.

Titles, and feelings can change things greatly between friends.

And I'm 13

Would you rather have fun with your friend, or a title that really changes NOTHING? Especially since he doesn't understand the differences between friends, and girl friends, and doesn't want to lose what he has already.

Just be friends, and keep talking and having fun.