Step 1 -> Download plugin from authors site or the WordPress plugin database. This is generally in .zip format, and you need to unzip the plugin into a folder
Step 2 -> You will need to upload the plugin via FTP. For this you will need to have your FTP client installed
You can download FileZilla: Free FTP Client and learn how to configure it with your username and password given to by your web host
Step 3 -> Now you would have logged into to your website and you should see a directory listing as shown below. You should navigate to the directory where WordPress is installed, which is typically under www
Step 4 -> Now you should find three basic WordPress folders
Step 5 -> Navigate to the folder wp-content where WordPress plugins are located
Step 6 -> Now you can upload the extracted plugin folder with all files in the plugins folder.
Why don’t you check out the following plugins that will enhance your WordPress blogging experience