I don't use social media, so I can't answer the first question.
If you want to get off the internet a lot, you have to go out and do something.
Fun hobbies are acting, kite flying, reading, cosplay (dress up), online role play (participate in a rich battle as any character you want), scrapbooking (make a book of all your memories), live action role play (dress up and play in a rich fantasy world), swimming, sports, yoga, Lolita (dress up in fashion inspired by the Rococo and Victorian periods), and many others.
If you want to learn more about cosplay, online role play, live action role play, and Lolita, look them up and get some answers!
If you want to get serious about any of these hobbies, talk to your parents.