To install a plugin in WordPress, go to your website dashboard, and then click on Plugins → Add New.

Then just type the name of the plugin that you want to install and click on Install Now → Activate

Or if you have the file of the plugin (which usually comes in RAR format) you can press on Upload Plugin → Choose the File → Install now

After it has been installed successfully on your website, you will be able to activate it.
How to install WordPress plugin manually
To install a WordPress plugin manually, you need to upload it from your website file manager in your hosting control panel.

After you open your file manager, go to your website file where WordPress is installed. Then go to wp-content → plugins and click on the upload button.

After you upload it, right-click on it and press on “extract” (or you can find the extract button on the line above). Then go to your WordPress dashboard → Plugins and you will find the plugin that you just upload it and you will be able to activate it directly.
how to install WordPress plugin on localhost
To install a WordPress plugin on localhost, you need to extract it on your website plugins file, which can be found in your site → wp-content → plugins. or if your localhost on Xampp server, you may find the plugins file on C:\Xampp\htdocs\8y35\wp-content\plugins.
Then extract it there and you will find that it has been installed on your website, and all what you need to do is to activate it directly.
Manual uninstallation
To uninstall WordPress plugin manually, you just need to delete it from your file manager in your hosting control panel. and it will be deleted from your website.
These are the most known ways to install a plugin in wordpress. if you have any question feel free to contact me and i will do my best to help you. Thanks for reading.