So I've logged over 550 hours pubbing on my current account, with probably a few hundred on my old account, and I've always wanted to try out competitive and really test how good I am, but I didn't really know how.

Yesterday I thought I was pretty good. I make mvp on the pubs I was on pretty regularly and I thought I had a good understanding of the game and how to play.

Then my friend told me about sites where they organized highlander and 6v6 games and I decided to try a couple out today, and holy crap I am so bad. I had the most deaths in either game I played. The difference between pub servers and competitive is absolutely flooring.

Do the experienced players here have any general advice or strategy? Maybe an easy class to start off with? For reference I played my games as Heavy, and my best classes on pubs were Heavy, Engie, Demo, and somewhat Pyro.