I want to ask my crush out but I don't know if she has a boyfriend. How do I find out without seeming weird or her knowing I like her?

The best way is to just be straight forward.

No games.

Girls don't like games, and will respect your honesty.

casually text her and ask if she wants to meet you for coffee, or invite her out to some event (this way, it doesn't necessarily mean its a date, nor friendzone either).

Rejection could happen, but test the waters first with a simple invite. if she blows it off then she may not be interested. I don't know what your current status is with this girl. are you close? are you friends for a while? whats the history? all of this plays a factor. just be yourself. be 100% and youll get 100% answer from her.

Lol omg just say hey do you have a bf? Lol if she's why I mean say because I wanted to ask you out but I needed to know if you were on the shelf or not duh lol

bring it up casually

Play truth or dare

but be sly

If you can ask a friend to ask her