Im 19 also. My ortho wanted to put braces back on me and i told him to go to hell and didnt go back. Who really cares if your teeth are slightly off?
Get them, your teeth are not terrible but definitly not straight, after your done they will be perfect.
Plus they will prevent expensive, painfull, and annoying surgeries you will need later on in life.
And people don't even notice braces except maybe like the first day. When my friends all got their braces taken off I had no idea and I could never tell you who had braces and who didn't.
I had invisalign which is great but annoying becuase you have to take them off to eat everytime and they can get super dirty and some people notice them but if you have the funds then get invisalign over regular braces but there are pros and cons