Hello @schucri,
To change the text of the Read more button, you have to create and activate the child theme.

For this you can refer to below link:
https://codex.wordpress.org/Child_Themes
OR
You can also create the child theme using plugins and below is the link to one of them.
https://wordpress.org/plugins/wp-child-theme-generator/

After creating and activating the child theme, in your child themes functions.php paste code of the below link:

And we also want to inform you that the theme is already translation ready and can be translated to any other language.

Hope this helps,
Best Regards!!

Hello @schucri,

The Strings of the theme should also be manually translated.
So, Please follow the instructions below:

– At first create the “languages” folder in the location, themes > blog-pro .
– Create the .pot file required using the software like Eazy Po
http://www.eazypo.ca/
– Place the .pot file inside the languages folder you have created .
– Using this file you can translate to any language you want.

For this you can use any get text editor software like :

https://poedit.net/

You can download the software where you can see many option for the translation.
Now you can choose Create new translation and then select the language of your choice .
Here you can begin to translate the string of you choice and save it. Now it will create .mo and .po file in the theme languages folder.

Also please go to Dashboard -> Settings -> General and on the bottom you can see Site Language option change it to your language.

Hope this helps.

If you any confusion further, please let us know.

Best Regards!!