How to prevent bike from jumping up when first getting it rolling?

Just keep practicing. That is really the best advice.

Clutch control is the key, try to let it out slower/smoother and be smoother with the throttle. One fluid motion. Let out the clutch slow until it engages then let it out more. At the same time roll slowly with the throttle.

Give it time, don't get discouraged because you will look back on this email next month and laugh because by just practicing you have mastered it!

Also, sit farther up on the seat (closer to the handlebars.) This will reduce wheelies in any scenario.

You can also put your elbows up and head slightly over the bars to help stay in a good attack position.