The world of Overwatch is divided into four different classes: offense, defense, tank, and support. Each of these classes has a different role in the game. We highly recommend sticking to one class and mastering it, but not at the start. If you're a new player, try experimenting with at least two heroes in each class. It'll get you a feel for the game and allow you to get better at the fundamental basics. Once you play everything, you'll know exactly what class is more suited to your playstyle.
Socialize your puppy