Hello @juanmacordo,
As for the page title, the title comes from the page name. If you want the title to be translated then create the page naming ” WP Travel Cart ” in your language and assing it to work as the cart page.
For this go to Admin Panel > Trips > Settings > Checkout Process and chose the page for cart page.
For confusion please refer to below given screen record.
https://www.useloom.com/share/2181e8c691334f989950b13bbcd6477b
Follow a similar process for checkout.
Do not forget to paste the shortcode for cart page and checkout page for the pages that you have created.
Link: http://wptravel.io/documentations/user-documentation/settings/general/
Hope this helps.
Regards!!