I would help.. Lel.. But I probably wouldn't know cause I'm 14....... And I've never had a bf or anything.. Idk. But it really depends! The girl might be into certain things and every girl is different with different opinions. Usually if you become best friends that's probably a really good sign that she's into you but maybe not necessarily romantically as they may be a tomboy sort of girl and hang out with guys more so than girls naturally. If you share the same hobbies and the same interests it is always good but communication is a really important thing in a relationship as well as respect and being able to handle any arguments and negotiating plus every now and then letting them know how you feel. Also, some girls may be looking for a particular thing in a man, for example: Christian, or trustworthy, or good looking or same interests or nice personality that is good to be around for example. It's really hard to say though and I'm not an expert or anything sooo yeah..
Also, it's best to start a relationship when you're ready and not at a young age. At 14, you're still growing and whether you know or not you still need maturing emotionally, physically and mentally up until you're 23 I think..

but yeah.. If you feel like she's the right girl than go for it but remember to treat her like you'd like to be treated and be yourself and don't let go of your own personality to be someone you're not! Good luck!
That's the best I could think of. If I knew her I'd probably be able to help more..

hope you can end up finding the right girl even if she turns out to not be the one anyway!!