What are some fun things to do on the Internet with no friends?
Just pickup any random skill and start learning, don’t worry about the outcomes, just learn it. You never know when that skill will become useful to you in the future. Steve jobs took a class on calligraphy during his college days, and that skill came in use when he was designing fonts for the word processor for the first Apple computers So you never know. Visit sites like - skillshare, edX, coursera, Udemy or YouTube, Pickup any random skill and start learning. Practice that skill for atleast 20 days and you will become good at it.