So I like this girl at work..but she's straight ?

I met a girl at work a couple of days ago, it was the first time we had worked together on the same shift but it was only like my second day. All she was really doing that day was just showing me the ropes of everything and helping me, but by the end of the night it had turned into a crush. She looks a little older than me (17-19 around there) and I don't know anything about her so I just call it a crush, I just think she's really really cute. Im trying not to obsess over it for the next few days cuz when I go back if we work together ill be more awkward and I'm also trying not to get too involved before I even know her.

So how should I approach this? Should I just keep my distance or should I hint around at it? I don't want a relationship with her cuz it's work related but that's not to say we couldn't be more than friends outside of work.

Also I'm bi and I think she might be straight but I'm not positive so how do I find out what she is without flat out asking?

Thanks