I've had IVs lots of times. They aren't so bad if you get used to it. I didn't use to look when they were putting the IV in, and it helps. I have to give myself shots often, and they don't bother me at all anymore.
I've been put to sleep for procedures a few times. For me, it wasn't bad. I just felt really sleepy and then when I woke up it was all over. They usually check on you to see if you are ok. They will try to offer you something to drink if you're not feeling nauseated. You usually have some time to wake up and start to feel normal before you have to get up.
I had to wear a hospital gown every time, but maybe you won't need to. I didn't like them because they are always much too big. If you have something to listen to music, you could probably put headphones on while you wait. That helps me to relax.