I have one, and once you get one you realize that the only difference between tatted people and people without tats is that people who have them don't care if you do.
There is a big stigma towards them but I personally like tattoos. Here's my advice if you're looking into getting one.
1. If you're getting words, get them in a language you are either fluent in, or have history in. For example, my friend who doesn't speak french is getting his family crest with french words beneath it. He knows what the words mean and the crest has been in his family for a long time so it's okay. In any other case though, never get tattoos in a language you don't speak fluently.
2. Don't get fucking tribal tattoos.
3. Think of what you want, draw it or have it drawn for you by someone online (reddit can help for this), and set it aside. Look at it everyday for a month and if you still want it at the end of the month then get it.
4. Make it meaningful, but also make it represent something you don't mind talking about often because once you get it you know people are gonna ask you about what it means.
5. Think about placement. Feet, hands, collarbone area, ribs, etc (anywhere near bone) will hurt a lot. Then again, if you're even the slightest bit worried about the pain then you should NOT be getting a tattoo.
Other than those pieces of advice, the biggest one I can give you is to have fun with it. Think of it as a way to customize yourself. Think of it as a way to retain memories. Don't make any stupid decisions and you'll ultimately be happy. Last but not least, a slight warning - tattoos are addicting.