Well of course your new Gaming PC will be for playing games! However, what games you want to play is the most important question you need to answer.
The type of games. and even simply specific games will set the level of hardware you need.
Your selected games will also set the budget for your new Gaming PC.
Research the games you want to play, check out those games with others, and decide just how many games, and exactly which games you want to play.
This will help you on your way towards the steps of selecting hardware.