Working on my riding skills

First ride on the actual mtb trails in 2 months since I was on vacation. My bike is in desperate need of service as-well so I use my friends, dad’s bike- the transition setinal and it was so dope. I’m trying to work on my riding position and just riding in general and I’m quite happy with how I rode right away coming back as on my old bike head would shake a lot. Today really suprised me and I would love someone advice and pointers- thanks!