This is a website called Imgflip where you make memes and share them with people, it was originally created in 2008 by Washington (a private university in St. Louis, Missouri) graduate Dylan Wenzlau, but became public in 2012. The site's primary streams are the politics stream, the cats stream, the repost stream, the fun stream, the gaming stream, and more. Most users use the fun stream, but the largest non-primary stream is MSMG (URL imgflip.com/m/MS_memer_group), which was created in 2020.
I recommend you to post in the Vibe_Zone stream (URL imgflip.com/m/Vibe_Zone) until your account becomes old enough on July 19th. Create your own posts intended to contain humor, or repost material from any of the recommend sites or specific parts of sites:
r/shitposting (https://reddit.com/r/shitposting)
r/whenthe (https://reddit.com/r/whenthe)
iFunny (https://ifunny.co)
Or older memes which have been posted by other users, yet not so recently that people will remember them.
To learn more about the site and its history, I recommend you read every single page found on the MSMG wiki (https://msmemergroup.fandom.com), although I should warn you that there is profanity.
MSMG also has a Discord, found at https://discord.gg/fTZeStxkhJ