Practice other tricks such as manuals and Ollies so u have better balance then come back to it in about a week or two

I agree with the last commenter, but if you are set on learning fs 50s you should start with practice olling up a flat top curb with the same run up you would have with a 50. If you find your balance olling up over the ledge I’m sure that you can figure out the balance when locked in. Also, make sure you land with your knees bent so you can have the lower center of gravity which provides more stability.

Lean back away from the obstacle as u do it.