is 1200 elo good for an 18 year old?


A 1200 rating in any time control is better than the average here. It is good if you feel good enough to enjoy the games you play. It is not good if you are hoping to become world champion.
If you hope to improve, you should start taking the lessons offered here more regularly.
They offer the tips you are looking for.
It depends who you compare too.
Here is the rating of another 18 year old:
https://ratings.fide.com/profile/12573981