How to play in Steam?
Gosh... This is not easy, but let's try it!
First of all. You will find a couple of buttons on the left, Buy the game... Play now... and Lobby... The first one redirects you to Steam website, where you can buy the Definitive Edition game. The second one, will launch the Steam client plus the game inside your computer. The third one, will open the online lobby website that was made by SkittishDeer. There you can apply custom filters to have a better lobby experience. But there's no social chat unfortunately.
The purpose of this tutorial is to let you, know how to play DE in Steam. For that, you can click on Play Now button. Then it will ask you that the browser is trying to open Steam, click open, and wait for the game to open. Once the game is open, click Multiplayer, then Personalized Match Game, and you will found a list of games to play with. just double click on any game that has available spots and then you will know what to do!
Another way is to click on Lobby... If you see, there you will have a list of games, let's talk first of the page content... In the top right corner, you will find Lobby and Spectate, if you click Spectate, you will find all the games that are available to spectate right now, just look up for your desired game, and then click Spec button.
Back to the Lobby, we can see a list of games, I recommend to you to press filters button and add your desired filters. Inside the list of games, you can see whose players are in each game, you can also click on JOIN or STEAM to open the game, also you can copy the game ID for other purposes. Once you press JOIN, you will be automatically got into the gameroom, unless it's full.
Thanks for reading this!