Help?

[Magicnachoz]

Where do I put these custom plugins? I can not really find in any of the posts saying where to put them

[Magicnachoz]

I want to add some of the addons but I don't know how I don't have SVN by the way

[JamminR]

The question you have isn't so much Ulysses related as it is "I'm new to Gmod, how do I <do anything>" and I therefore moved it to OffTopic.
That isn't a bad thing (we were all new once), but, the question you ask is quite publicly published at many Gmod forums, and although I didn't search, bet Google would find your answer on the first page of results.

I recommend you start here - http://wiki.garrysmod.com/?title=Main_Page
It's the 'official' wiki full of instructions, the manual, and tutorials for various Gmod items.
The specific answer you're looking for is in the "manual" portion, "Beginning Garry's mod"

You'll learn that most of us devs, and the other community members, are much nicer if you're asking a question about something not already answered, or at the least, asking about something you don't understand but have direct information about.