You can quit in many ways but i will show you two.
In the lower left corner it should say something like "Quit", you need to slowly move your mouse to the text, wait 4 seconds then quickly press quit. You can see what the "Quit text" looks like in the picture. Just be careful when doing it. You can also just press ALT+F4 if you just want it to be done quckly. (You have to press the letters not the red circle)

Edit: If you didn't understand you have to press quit in the game not on the picture you need jesus.

There are two ways to launch the game. The first option is to find the game in your steam library and then press the blue bar which says play. The left arrow in the picutre is poiniting at it.

The other option to launch the game is if you have a desktop shortcut of the game in your desktop.
Then you just double click the shortcut, YOU HAVE TO DOUBLE CLICK IT OTHERWISE I WILL FIND YOU (don't ask). Just don't forget that you have double click ON YOUR DESKTOP not in the picture. Yes

Hope the guide was useful

HOW TO ENTER A MATCH

Step one press US, US2, US3, EU or EU2 in the left upper corner of your screen while you are in the main menu. Step two press the letters AS which is marked in the picture inside my homemade circle (The arrow is pointing at it). Then it should say AS in the left corner of your screen now. You have to select the Asian server because it's faster at calculating algorithms.

Step 3 Hover your mouse over to the middle left side of your screen, it should be a text which says "READY" there. Step 4 Press it then wait 20-3600 seconds or even more (If the dot isn't going left and right then you should redo the tutorial). After you have found a game you are in the loading screen then it shouldn't take long until you can play so be happy. Red