Which mechanic will help this OG player rank up?

So I've been playing this game on and off since 2015, totalling around 1100hrs game time.

I've come back after a break of around 3-4 years, and the skill gap has obviously increased massively, with people pulling off shots that were never seen previously.

I'm managing to hold a rank of Champion 1/2 in doubles, but I'm definitely not as mechanically skilled as the rest of the player base around the same rank.

Basically, my entire rank is based on gamesense, and just putting myself into good positions. My accuracy is decent, as is my defence, but I don't know how to do any of the higher level mechanics. I can half flip, though I forget to do this most of the time under pressure of an actual game. I can aerial, but not the best at dragging it into the goal.

I can't: Speed flip, Flip reset, Musty, Any of the flicks, Roof shot.

Which mechanic would be the most efficient for me to learn first?

I'm about 30 hours into using DAR, not great at it yet.