When you finished each game, you will be given some points and EXP.
Inside the red box,it shows the points that you gain from the last match.Besides red box, green box shows the EXP that you gain from the last match. Yellow box shows player's clan.
You can check your current points by just clicking the red box in the main screen, the purple color box shows the current points that you have.
When you collected enought points, you can buy new weapons