Hey there pemurillo,
It looks like you're trying to set up Family Sharing with your Apple ID, but its not allowing you. We're happy to point you in the right direction for assistance.
Take a look at this article, and make sure the account meets the requirements to set up Family Sharing: Set up Family Sharing. This covers the stipulations and requirements for Family Sharing to work properly. If you need additional assistance beyond the steps in the article, we'd recommend reaching out to our Apple ID team in your country. You can see support options here: Get Support
Cheers!