Your plugins folder is located within your “blog” folder.
If you look in your local files, it’s probably here:
yourblogsitefolder–>blog–>wp-content–>plugins
So, once you’ve downloaded a plug-in folder you want to add, you’ll just drag that folder directly into your plugins folder, as outlined above. (If it’s a zipped folder, be sure to first extract the contents, then drag the extracted folder… i.e. do not drag the zipped folder into your directory.)
The path would then look like:
blog–>wp-content–>plugins–>”yourpluginfolderhere”
Once that’s done, you’ll need to ftp it to your remote host server.
Next, go to your WordPress dashboard, and the plugin should show up under the Plugins tab. Click the “Activate” tab that appears next to it.
Hope this helps!