I made it to the div1/prem area 2 separate times both on med and spy at one point and for me it was mostly about knowing people and trying to be chill.
Merc as much as you can and play pugs etc. Unfortunately a lot of the higher div teams can be a bit circlejerk-y, but I found that once you got into those circles it all got much easier and people will almost come to you with new team prospects. People also seem to usually be willing to give you a bit of slack on the game play side of things if you're open to learn and improve during the season.
If nothing materializes right away then just work on yourself in div 2 for another season, nothing wrong with being more confident in your abilities. Best of luck!