hey Mysterie, that's so awesome that you are shooting film! are you going to have it lab developed? if so, it should develop just fine. negative color film gives a lot of latitude or room for mistakes concerning exposure.
biggest thing for shooting friends is have the camera out and start taking photos right away. like don't start hanging out and then randomly whip the camera out. if it's there from the start, you and everyone else are a lot more comfortable with it. sometimes i take some garbage photos when i first arrive, knowing i won't use them, just to get myself and everyone else comfortable with the fact i'll be taking photos. doesn't mean you have to take photos the whole time either. if you start off taking photos, it will be fine if you stop for a bit and then start again.
also get them excited about it. everyone tries to act humble or shy in front of a camera, but reality is they want to be photographed. say shit like "i think that one's gonna be really great" as you snap away. be sure to share the photos once you have them developed too, and only the good ones. if people see that you make your subjects look good, they'll be even more excited to be photographed by you. take lots of photos to make sure you do end up with some good ones.
with friends, i actually do not recommend asking first. just start taking photos. if you ask people, you'll get false no's. like how people who were excited to share their work in class acted like they didn't want to but secretly hoped the teacher called on them.
and don't worry about resistance. sometimes my friends roll their eyes or lightly say, "geez, when are you gonna stop?" but then the next day they are asking "hey, when are you gonna get those photos back? are there any of me that you're gonna use? when can we see them?" again, people are trained to act shy in front of the camera. don't worry about it. if someone truly does not want to be photographed, you'll know. and that's just fine. though the more you photograph, the more you'll get comfortable pushing people, and you'll find that some of those people actually do want to be photographed.
everyone wants to look good, and it's very possible to make people look good with a camera.
hope to see some of your shots!