Losing speed and cant move up and down the wave

Hey Guys,
Im a beginner and i started going along the line and i catch most waves i paddle for. If im on the wave i quickly use speed and i dont really know how to perform a buttom turn. The video attached is me surfing a wave and it shows well, that i can really get down to the bottom of the face and that I lose speed. I also think that my weight distriubution is not very good either. Can anyone help me? Thanks alot!!!!
The link to the video:
https://vimeo.com/932371357?share=copy
Im a beginner and i started going along the line and i catch most waves i paddle for. If im on the wave i quickly use speed and i dont really know how to perform a buttom turn. The video attached is me surfing a wave and it shows well, that i can really get down to the bottom of the face and that I lose speed. I also think that my weight distriubution is not very good either. Can anyone help me? Thanks alot!!!!
The link to the video:
https://vimeo.com/932371357?share=copy