How to translate strings in theme?

hi

I have some issues with the translation of the theme. some parts are not translating like the button “read more” or the words at the end of the blog “share this” or the form at the end of the blog “your name, your email , your web page” . I’ve installed my wordpress in spanish, but still need to fix this specifics.

Can you tell me wich files do i need to modify? (wich lines of code if possible)

Thanks in advance