There is a billing problem with a family members previous purchase

I tried to get a free app on my App Store and that message came up. I wasn’t even aware I wasn’t on a “family” membership. And when I checked who was the “family” was managed by, it was a random icloud email I have never seen or heard of before. Then, I checked to see my “recent purchases” because I don’t remeber buying anything since my credit card is linked to my Apple ID, it says I tried to purchase Minecraft for $6.99 or something. I didn’t make this purchase and am very confused what’s going on. When I tired to update my credit card information it wouldn’t let me. Did someone hack into my Apple ID or something? I’m very confused. I called apple and the automated voice thing told me to come here. I didn’t have this problem yesterday.