I accidently deleted the thing that has the prefabs and stuff. It is like the hierarchy and inspector but it hold the other things

@Rosander11 I assume you mean the Project View? If so, then either click on the "window" tab at the top of the editor interface and select project, press ctrl+5 or click on the layout drop down box at the top right of the interface and select "Revert Factory Settings". Any of these should bring it back. If this isn't the case, then please take a screenshot so that I am able to see what it is that is missing from your projects.