Are you new to s&box? Starting from scratch, another engine or Garry's Mod? Start with the steps below, then use the docs, tutorials and example code to start building games, addons and content.

Download s&box, have a look around the engine, then start a project of your own.
Grab it on Steam. The editor and the game are the same download, so there is nothing else to set up.
An existing scene you can break safely. Move things around, hit play, and see what a GameObject actually is.
An empty project, one component, one key press. By the end you have written C# that runs in a live game.
The parts of the engine you will be working with.
Build a world out of objects, hang components on them, save the lot as a prefab.
Write a component, save, watch it reload in the running game.
Move around the viewport, manage your assets, wire up logic in ActionGraph.
Input, navigation, terrain and VR, for when you need them.
Turn a single-player scene into one other people can join.
Shaders, shader graph, visual effects and post-processing.
Everyone does. Here's where to look.
The forum is the best place for a question - it stays searchable for whoever asks it next.