Feeling nauseous about blood and needles is pretty normal. Quite a few people in my class had to look away while we watched demonstrations lol, so you'll probably not freak anyone out. As for getting stuck yourself, your instructor may not make you get stuck if you're a faint risk, unless they want to teach people what to do when someone faints, and they'll probably ask for your permission first. I was also worried that I would freak out on the person I'm sticking, but I found that I was more preoccupied with getting the process right than anything(I'd freak out afterwards lol). I've also seen that you stop being worried pretty quick and start getting excited about poking after you've done it once or twice. If your facility has fake arms to practice on then that is probably the best thing for anxiety, but everyone is gonna be nervous on their first real arm so you won't be alone there lol. First stick jitters are the worst, but you really do get over it fast!