Time to leave the browser sandbox and open the real tool. Roblox Studio is where your Lua actually meets a 3D world, and the first thing to get comfortable with is the layout. Two windows do most of the work, and once you know them, Studio stops feeling busy.
The Explorer is the tree on the right. It lists every object in your game, nested like folders. Workspace holds everything you can see and touch in the world. When you add a Part, it shows up there. Think of the Explorer as the table of contents for your whole game.
The Properties window is its partner. Click any object in the Explorer and Properties fills up with every setting that object has: its name, color, size, position, and dozens more. This is where you’ll change things by hand, and later, where your scripts change things automatically.
Run through the checklist in Studio. There’s no code yet, this is pure orientation, and getting fluent at “click the thing, find its property” makes every lesson after this faster. When you’ve inserted a Part and renamed it, mark it done.