Multi language site

I need to add multiple languages to the site. I have Shams Solar Pro template and i need to be able to change the templates content with the relative translations of the differents languages. I have Polylanguage plugin for my pages but it can change only my pages content and not the content of the theme which i can change only in the customize section. Someone can help me please? (I didn’t add the link of the site because it is not published)