It’s practical (nice start) but ugly. If you want to become a good Derma coder, you need to get an eye for what looks nice. For example, you should (in my opinion) center the left menu vertically to avoid making it look like you just have a bunch of empty space, or merge it somehow with the right menu to avoid extra grayspace. Also, padding. You need it. In the collapsible categories, your derma items should not be on the border - it looks better with some space inbetween.
And lastly, I would suggest adding a space for an RCON password on multiplayer servers so it’s viable in all facets of gmod.
Oh, and don’t use the default frame. It’s really dull because everyone uses it. Try overriding the DFrame’s paint and use a rounded box that’s black or white or just something besides what it is now.