I've had several facial piercings, some I've pierced myself, and from my experience getting one is a personal preference which might seem like such an obvious statement but asking people about how they feel about something you're going to have on yourself is pointless.
The people that might judge you will be strangers. It's most likely their ignorance and assumptions that you might come across. The people that 'know' you won't care. By 'knowing' I mean people that you have close relationships to. Parents however might have another opinion to your choices.
Your workplace will be affected to some degree because of appearance or occupational hazard. You can get clear jewelery called retainers that make the piercing not so obvious. With a lip piercing your gum can recede but if you have a great piercer, appropriate sized jewelery and good health and hygiene practices it won't happen.
With my own lip piercings I replaced the flat back barbell jewelery with a ring because the back of the barbell was 'sinking' into my lip (the pressure of the bar was making my lip rest over the backing). The reason for that was the back of the barbell was too small in diameter and the bar was too short. Problem fixed.
I've never had anyone treat me any different because of my piercings. I might get a rare 'doesn't that hurt?' comment once every few years but people get over it quick, it's so common these days I think a lot of the older prejudice doesn't make sense.
FWIW, I don't think you should get one because you have doubts.