Regardless of any other advice you get her or some other place, the most important thing to do is to go develop that film.
We can tell you everything you need to know and a whole lot of stuff you probably don't even want to know but, until you put some film in the can and shake it up, you won't get the practical experience you need.
You WILL screw something up at least once. That's the breaks. Everybody does it. I have screwed up and I will screw up again.
The important thing is to learn from those mistakes.
In a funny way, if you aren't making at least a few mistakes you aren't learning anything.
Best advice: Just do it!
Then come back, afterward, and show us what you did.