Grab onto the "void" of each of those windows (Groups, Texture groups, Visgroups and "Move selected") and drag it to the right
Also, go to "View" at the top and disable the manifests for now, personally I have never used them and IIRC UEAKCrash recommends disabling it in their tutorial series because it's not that common.
Here's a visual of what you need to do, Blue asterisk is click and Red arrow is drag:
This should clear up space and resize the hammer
Viewports