There are different ways to install depending on the type of plug-in. For Nyquist plug-ins (files have a “.ny” file name extension), the plug-ins should be put in the “Plug-Ins” folder where your current version of Audacity is installed.
VST plug-ins should be installed according to the plug-in’s installation instructions.
If you click on the “Enabled” option at the top of the Plug-in manager, do you see them listed as enabled?
If you need further help, please tell us exactly what the plug-ins are (or at least some of them).
No, that’s the thing. The plugins are all in the correct folder but when I go to the “effects” within Audacity, it asks me to enable plugins, then there is a list of plugins, but some of the ones I have in the Audacity folder are not listed in that list at all. For example the Butterfly plugin. Even though the plugin is in the folder.