In order to create a legal template Go to 'Create Page'
Select type of site you have. If you also leave it as 'All' and select the type of template you want.
On the right hand side of the dashboard, you can see a list of templates.
In order to use a particular template, you need to click on it. The content of the template will be displayed to you in the editor. You can edit the template as you want, if anything is not applicable for your site.
Once you have selected the template, all you have to do is publish it.
Similarly, you can add other legal pages to your WordPress site.