How can I find opportunities to talk to the girl i like?

[Bob]

Ok so im a freshman in high school and there is this other freshman girl i like. I used to talk to her pretty frequently during 8th grade because we had classes together and sat at the same table a lot and stuff. Now, I don't have any classes with her. We walk past each other in the hallway usually like 1-2 times a day. Sometimes i say like "hey" or "hi" but not everyday since it gets awkward if you do it all the time. I want to be able to find opportunities for me to get to talk to her. Also, she is not in the same social group as me. It's not like shes "cooler" then me at all though. Furthermore, I dont really know her friends that well. I did get her phone number while talking with her on facebook and we do text like 2-3 times a week, but I WANT TO TALK TO HER IN REAL LIFE THEN ASK HER OUT. Lastly, I'm pretty sure that at some point in 8th grade she liked me back but im not sure.

How can i find opportunities/times to talk to her without seeming desperate?

Thanks a ton