To answer your question...I doubt they will tease you or anything. Tumbling will come in time and so will jumps but to improve them you should sit in the splits for a while everyday...a great technique is to hold each side for 2 minutes every time you get a text...if you text a lot ask one of your friends to text you a reminder like every 30 minutes or to start try every hour...also do squats and frog jumps to increase the height of the jump. Also a few years ago my coach made us all buy ankle weights and do jumps in them taking us up a point and a half on the score sheet. Pike ups are also a MUST for good jumps.
As for your height consider it a blessing in the cheer world you're probably going to be what's called a back for stunting to prepare a little do push-ups.
Stretching is a must for jumps and flexibility. Try touching your toes, doing lunges, and doing basic split stretches. Most cheerleading squads will introduce you to new stretching techniques anyway. Just try to get in shape by stretching.
Remember that not all cheerleaders are stuck up and rude. Just be nice to everyone, and you'll find a place to fit in soon. It worked for me. (:
Just don't do it. Because it isn't a sport. Is clapping and yelling a sport?
Why is this under the sports section? Cheerleading isn't a sport