Sin I am going to be a little harsh to get you to view your videos clearly, ( they are a great way to help though)
You are surfing two separate halves, the top half is flailing arms swapping away a swarm of wasps but producing little effect on the motion of the board, your upper body moves around the waist line but the energy you generate does nothing to change the board direction, feels like you are doing a lot, doesn’t it. It also disturbs the glide of the board on the wave face (OMS) is right in suggesting a longer board might have helped you more.
Now the lower half, not a lot of movement in the whole system an occasional knee, , your feet are concreted in one position a bit more towards middle forward of the tail, short board require weighting and unweight of the feet and ankle movement supporting the heel and toe pressure.
Your turns are largely based on leaning but the beginning basis to surf well has some minor shine outs, you are making sections, your slightly forward position is giving you a little trim speed combine that with some controlled energy from your upper torso with intent to change board on water you will start to surf better.
Secret effectively using the tail and tail pad for application of pressure to drive turns is a vital skill.
Watching, adapt how the better guys surf on their short boards, video them, since you are there it will give you insight as to what they are doing.
Get more videos of your own surfing post them, self critique , Question what could i do better in that wave?
Early beginnings, Balance , coordination of movement and effective transfer of your energy will come, stay stoked

I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷