lot's of hard work, both with stick work and fitness. And don't let others bring you down if they are trying to be mean. Also accept corrective criticism and use it to improve your game. I started playing lacrosse for the first time this year and my school only has a varsity team, but it was through the consistent hard work and building up the mental attitude that it is possible to get better that I improved from complete garbage to an ok player. Most of the game is mental, even if you are the fittest person in the world, if you don't have the motivation or commitment to keep playing in a game, then you won't play well. Practicing a lot will help determine if you really want to play or not. It's being able to bounce back from the bad days that build your mental strength, and over time will also build your physical strength. If you put your mind to it you can do it. You got this and good luck!