Let me give you a tip, but this may sound irrelevant as I'm a beginner to parkour as well. I would suggest you to do some parkour that involve no zip lines, as it would bring a much better practice in jumping towards a block. I would suggest "Parkour city C" and "Parkour city D" I forgot what the mod is called but it should be below the mod that you were playing in in your video. Btw you made me laugh my arse off while crawling helplessly on the ground. On that case, try learning to jump off your knee or elbows to at least stand up. From standing up and getting a footing, you can turn your body into a position of running, where you lean forward with both feet on the ground and contract and extend or relax hips and knees to start running. That would take practice, and obviously like everyone says and actually works... practice makes perfect.