Well, let's see. I wore glasses since I was ~5, then I moved to contacts when I was 12.
Working in an aircraft maintenance career field, it is highly unadvised to (and in the military against regulations when deployed) wear contacts at work. We come into contact with oils, acids, bases, etc. We work in dangerous situations with at times extreme conditions. It is advised not to wear contacts in case we get a chemical in our eye, or a piece of metal goes through our eye, or the wind dries our eyes out and the contact falls out, or even the fact that being deployed makes it EXTREMELY difficult to properly sanitize your eyes so they don't get infected. They reinforce all this with pictures of past events, constant reminders, etc. I know plenty of people that to this day still wear their contacts regardless.
If you work in a dangerous area, it is easier and safer to just wear glasses, however it just takes some common sense and situational awareness to make it an easy alternative. Know what you are working with and what kind of safety measures you are suppose to hold in place for dealing with it. Those safety measures are there to keep stuff OUT of your eye, whether you are wearing contacts or not.
I have gone off on a ramble now, sorry. Basically your eye doctor will tell you how to properly wash, wear, and store your contacts. They will usually pick a good type for you depending on your eyes' sensitivity and dryness, and they will give you a prescription. Follow what your doctor says. Putting in contacts is not bad, just takes patience and practice, and the doctor will show you how to do that also. Don't worry about contacts being to large or small, if that is a problem the doctor will also inform you about that, so you don't have anything to worry about. It's a weird experience at first, but worth all of it, no matter what these people say. Try it, and if you don't like it, try it some more and see if you can adjust. If you still don't like it, then it's not your thing, and don't worry about it.
Last thing
I just had laser eye surgery a few months ago, and I can tell you now that the chances of your eyes getting fucked up are pretty much non existent now. However, with laser eye surgery, the doctor will not clear you until you have had two appointments at least a year a part AFTER you turn 20 or 21 (depending on the doctor) The reason isnt because it could fuck up your brain, but simply that you vision fluctuates as you grow, and if it doesn't stabilize, they can't shoot lasers in your eyes, hence the two appointments a year a part. Also it was literally the best choice I have ever made in my entire life. Ever.