You can add different language pages

-For example, you can have "about us" or "our cars" to link to different language pages. I would recommend first translating everything using translations first. 

1. Go to pages -> add new

2. Create a title, URL, text including any short code you need

3. Publish

4. Go to appearance -> menus

5. Select a menu to edit -> select your language or create new. Make sure it is set to theme location -> correct language. 

6. select your latest page, and "add to menu" 

7. add all menus you want on your home page.

8. Save menu. 

Note: you can now use language tags for all page short codes, e.g. [carrental_cars lng="en"] or [carrental_cars lng="gr"], etc. -> when you visit a page with that shortcode, the language page will automatically switch.