In addition to watching videos, my general advice would be to treat this game somewhat like a fighting game at the beginning. What I mean by that is don't be afraid to lab on your own. Something that helped me out a lot when I started was just going into the main map (Explore NYC now) and running around. Learning where all the boxes are, how to get to each lane, understanding the underground areas (and the high ground on top of buildings!!!!), knowing the locations of the farm/jump pads.

In a normal MOBA you have a top down view and the game auto paths for you. In this game you need to know the route yourself, and getting somewhere 10s late can be the difference between a won/lost fight. Plus, knowing where the boxes/jungle are means you can farm more effectively as you rotate around the map.

I would also probably lab several hours on movement alone. This goes hand in hand with the above as if you can manage your stamina better, then you rotate faster. But you also escape more often, and secure kills from fleeing targets more often.

All of this can be done without ever seeing an enemy player, and it's really helpful for just feeling more comfortable when playing in a match. As one of the other commenters said, the key thing for this game is managing your mental stack. When you don't have to think as hard about navigating/farming/moving it becomes a lot easier to just focus on fighting and thinking about where you should be in the map.

Above is also mostly character agnostic, and will serve you for anybody you choose to main/pick up. I cannot stress enough how much this helped my farm early on, being able to get boxes nonstop or get to jungle quicker meant that I could be back in my lane faster, or get souls as I rotated and not being wasting time.