The day I turned 18, I got an elaborate tattoo sleeve with a snake wrapped around a bomb on my upper left arm. It took 4 hours in the chair but I did it all in one sitting. It gave me a HUGE confidence boost for a couple months because I've been freakishly skinny my entire life and I sort of proved to myself that I wasn't weak. After a while, I stopped showing it off so much (I work in an office and we have cold whether for much of the school year where I live). But I probably should. People are always surprised when they see it and they realize that they've been underestimating me.
As far as the pain goes, it kind of depends person to person. For me, the outlining was the worst part. When they filled it in with color, it wasn't so bad. My friend had the opposite experience. You start to go numb after a while. Depending on how long it takes, by the end you will get a euphoric rush out of it because you no longer feel the pain. It's really empowering.
Spend a few weeks reading about all the tattoo shops where you live. Look at the artist's portfolio to see if you like their art style. Try to go to the best place you can afford, because you don't want to cut corners on something that will stay with you forever. I talked to my artist a couple of times and watched him work, so when I went in I was comfortable with him and he put me at ease. Some places are really elitist though. The last thing you want when you're getting a tattoo is to be around someone who intimidates you.
As long as it means something to you and you really want it, the pain isn't going to stop you no matter how bad it seems initially. Like, I said earlier I'm really skinny and beyond that I'm squeamish. Yet, I still managed to do it.
Tattoo parlors aren't really all that intimidating if you don't go to the ones run by massive muscular biker looking folk. You can expect the employees to be tatted up, but you shouldn't let it or the environment intimidate you, especially since you're there to get one.
Great goal! I have been wanting to get a small tattoo or even a piercing for years. People usually have a friend going with them when they get these things done, though... and of course I dont have any friends to go with me. I just feel weird going by myself