Unless you learned some truly bad habits from your first instructor, then it is never a waste of time! Even if you didn't learn latin per se, you still learned about latin motion in your rhythm as well as timing, musicality, how to lead, etc. which are all very important skills no matter what dance(s) you do!
Beside which, the most important part of dancing is, of course, to have fun!!
Best of luck and keep dancing!
