So, I recently got Sony Vegas 13, and was trying to make some audio edits. When I went to the Plug-in Chooser, there were no options at all. Do I need any other programs to get those options? This is what it looks like: https://gyazo.com/b80c1ccecad5318617499cec7349ac91
You should see some sub-folders and I believe there should be some standard plug-ins included. I have the last Sony-branded Vegas Pro 13.0 build 453, and this is what I see in the "Sony" folder:
Note that I also have Sound Forge installed, so some of my plug-ins are there because of that (e.g. Noise Reduction). If you have the MAGIX release of Vegas Pro 13.0 (version 543) then I assume all references to Sony should have gone, but you should still see plugins. I guess Vegas is somehow looking in the wrong file location for the plugins. You should make a support request.
Googling (Archive Search gave too many results as Nick also says in another thread) gave me an old thread, where a reset worked for a user. Try it, if it does not work, try uninstall, reboot, reinstall.
Close the program. Now press CTRL+SHIFT while double-clicking on the program's icon to launch it. You should see a window that asks "Do you want to reset all preferences to default values?" Place a checkmark next to "Delete all cached application data" and then click Yes. For older products, continue to hold the CTRL & SHIFT keys until the program is fully up and loaded.