Are you looking for information on how to get PvP gear? In SWTOR, you can get PvP gear by gaining commendations. You can start this at level 10 when you are first able to enter the warzones. You can get warzone commendations and mercenary commendations. By level 50, there are more ways for you to get PvP gear that you need and want.
After level 50 you can get the champion gear back, do daily and weekly quests such as warzones and Ilum, get the Battlemaster Gear Bag and more. This chart gives you a great visual on what you can get and where.
Whether you want to PvP as a main or just do some on the side when you have free time, these charts give you an easy way of looking at what you need to do.