Are you on wordpress.com or ww.wp.xz.cn?
Hey
In your dashboard on the left you should see the following
Post
Media
Pages
Comments
Forms
Appearance
Plugins
Hover over plugins with your mouse then you should see
Plugins>Installed plugins
>Add new
>Editor
Click add new
Then to the right of the page you should see a search box, just type yoast in it and hit enter
In the top right corner of the plugin you want to install there should be a install button, click install
then you should get the following message
Installing Plugin: Yoast SEO 2.3.5
Downloading install package from https://downloads.wp.xz.cn/plugin/wordpress-seo.2.3.5.zip…
Unpacking the package…
Installing the plugin…
Successfully installed the plugin Yoast SEO 2.3.5.
Activate Plugin | Return to Plugin Installer
Click activate and that’s it finished
<<< Make sure you read the yoast instructions/documentation and pay attention, this can negatively affect your seo of your site if you put the wrong content in there
Happy days:)