CrazyMyra@OutOnTheMoors@beige.party
I don't recommend this unless you're truly interested in the mechanics of social media manipulation, but a fascinating view emerges if you create a small, "anon" account on one of the big platforms. No avi, no details, very basic "bio".
Post one single text/image yourself (the more innocuous the better), repost and follow very rarely, and be sparing in your likes.
But be there, looking at stuff, regularly.
Very quickly, you'll discover how much the platform already knows about you.
(This is aside from the obvious stuff like location and phone type.)