How to store data from social networks?

Question

PHP

1) How to store data in the database when the user is authorized (for example, via VK api)? (I form a link, follow it, get a code, check access_token, it contains user_id, email)
Do I need to somehow hash all this? Or just open a session and write to it? What to store in the database? The question is more related to the security of authorization.
2) I have a city portal linked to an Instagram account. When posting news on the site, it automatically goes to instagram via api. So, if a post is commented on on Instagram, I want to display it (them) on the site.
But the question is how to organize it correctly. The instagram api has a /media/comments/{$id} method, you can pull out the comment text, author, author's avatar, what about avatars? To pump to itself a curl or to give as is?

Answer 1

1) if it’s safe, then don’t store anything
2) if you want to download a curl, if you want to give it away as is