Well this is all my personal opinion: I'd shy away from facial piercings. Statistically a large amount of people find facial piercings unattractive, so your dream sweet heart might be turned off my it. More than that, a piercings anywhere else is easier to hide. I have ten piercings, but they're in places where they can be easily removed/hidden so I'm able to maintain a professional job, appearance, and an essence of respectability; something that is really important as you get older. Also, if you ever decide to take a lip ring out they leave scars. Everyone scars differently, but they're usually noticeable if someone looks closely. Also, there's a higher risk for infection with oral piercings. I think lip rings are punk/hip, but they're not timeless; something you can love forever. A belly ring can be classy, punk, etc. Also easy to hide or take out eventually without anyone noticing.
I used to have my lip pierced when I was 19 with my bestie before it became the trend. I loved it. I always wanted my belly pierced but I have a bit of a belly so yea lol. That's out. I say go for it tho!
I got my belly button pierced and I love it! It just takes a little while to heal. I would think a little more into the lip piercing, it sounds like you got the idea from your friend. You might want to make sure thats really what you want. Dont just get one because your friend has one.