2. As in your another ticket, I just told you that you should buy the WPML plugin for the translating into multi language.
If you just want to use Spanish (without using any other languages), you can use Loco plugin. This is the free one, but you have to translate manually.
To edit or modify the cart, you can go to this path: wp-content/themes/turan/templates/headers/header-style-02.php
3. Cart and Check out page: We style these pages as the default template of Woo. So you can style override the current style or re-customize the template of Woo (you can refer the document of Woo to get more information)
4. Modify user info: go to this path to change wp-content/themes/turan/template-parts/header-userlink2.php
Regards,