Why is it that when I start a game..

I have no weapon? Cant use weapons or even STools.

Mainly happens when I start up on spacebuild game mode.

What version of spacebuild?

Post specs and by any chance,
What version of Gmod is it? 11? 10? 9? 12?
(Let the op answer this)

I thought you weren’t supposed to start with weapons in Spacebuild?

Well anyway, before you start the game, click “Play Singleplayer”, then click the “Options” tab that appears. In that, find the box that says “Start with weapons” next to it make sure it’s checked.

You are. He just has a broken version of Spacebuild.