what tees should i get my handicap off?

Normally if your under 18 and paying junior fees your only allowed to play of red tees (check your club rules) and this is where you would get your handicap from.

The par of the course doesn't have much to do with the h/cap, its the standard scratch you play to. (There's a thread somewhere explaining this).

From my experience all juniors play from red tees unless a single figure h/cap where your then allowed to compete in senior competitions for h/cap purposes only.

This is just from my experiences but I would check with your club to see how they work things. Every club is different.

Good luck.