Day 5 mountain biking any tips?

Focus on pumping before you start jumping. Instead of fiending for air look to pass over those bumps as efficiently as possible. As you get better those bumps speed you up and eventually give you air without you having to yank on the bars like you are currently doing.

Try to do a couple passes Pushing through your legs exclusively. Let your arms be firm, but absorb the bars as they move. let your legs do all the talking. This prepares you for pushing into jumps with your legs which gives you that pop you’re seeing out of other riders.