Layout Builder is not turned on by default. To turn it on for the Basic Page content type:

1. Go to Structure > Content Types > Basic Page > Manage Display.
2. Click "Use Layout Builder:"
   
   
    
3. Click Save. The page will redraw and the Manage Layout button will appear:
   
   
    
4. Click "Manage layout."
5. You are now editing the layout of all Basic Pages. Click Add Block to add Layout Builder Components. To make layouts unique to each page, go back to Step 3 and click "Allow each content item to have its layout customized."