When you click on the green Play button, you will see a popup asking you to download and install Roblox. Click the Download and Install Roblox. Save the installer file on your computer.

Sometimes you just want to play by yourself ... and “Available,” select “Offline” and there will be a green button which will broadcast your status to your friends and followers.

Roblox has a vast game library with something ... click the star-shaped “Favorite” button under the green play button. You can also save catalogue items for future reference.