theres this girl i like, and shes this amaziing fun and cool (9) girl, shes half japanese n german. but a closet nerd,which is fine, as i am. we usually see eachother in class and talk, i usually have social proof and dhv but on a subtle level, im not gona lie ive messed up a couple times, as i get ioi then iod. recently we finally hung out and she opened up on a personal level. she was in a insecure state because she had fake friends, so getting her to hang out was a prolonged process, i got her a pikachu plushie (shes asian ) and she loved it, and i was getting ioi's left n right, they kinda slow when i told her payfully "what about my kiss(referenceing the mistletoe card)". but i kept throwing in kino, i tend to have my push n pull mis calculated around her, hell its hard to focus around her. but later on she annouced during dinnershe had a boyfriend, in a subtle mention but i was unphased. Some other guy tried to hit on her during our bowling game (iod for me?) but i didnt do anything just bowled and beat my other 2 friends who came with us. (was i suppose to do something different?). now i talk to her more and we flirt but herboyfriend is another problem, luckily for me they met online via gameing system, so hes in Oklahoma, the down side is that hes seems to know what hes doing if he was able to get her through chatting, and hes a laywer who is gona buy a ticket for her to go visit him, and hes a lot older than me.

any advice to keep this girl?or to help?

You need to stop before you fall into the friend zone here. Start hanging out along without her's or your friends tagging along. You also need to make sure that you start adding a more sexual element to your interactions, whether that be just in eye contact, or in words, keep going with kino, build comfort in closeness, and when it comes to it, triangular gazing, and kiss her.

Ignore the 'boyfriend' situation, the way you mentioned sounded like they hadn't met yet, to me that just nullifies everything. It's going to be so much easier to move in on her when she's not even met this guy, and he has restricted contact with her.

Don't get friend zoned.