Spawn a portal gun in the spawn menu. Left/Right-click to shoot portals. Reload to remove all portals. To pick up an item, press E. If your portals don't look right on the other side, you need to ...

A game like Garry’s Mod is best experienced with mods, so we recommend going with a decent entry-level to the mid-range processor so you can run the game smoothly even if you spawn in a ton of objects ...