I did this trick of following myself on scratch! I will invite the peeps who wanna know! Just give me credit if you are making a project about it!
1: Sign out of your account and sign in your other account "If you have one".
2: Find your 1st accounts profile.
3: Open a new tab and go to scratch.
4: Sign out of your 2nd account and go to the first one.
5: Go back to the 2nd account tab then unfollow then follow your 1st account!
6: Close the tab with the 1st account then sign out the go to the 1st account.
7: Enjoy! :)
If i'm not clear watch this video(It helped me):