Go to the “Modlog” page at the very bottom of the web interface for your instance. You can search moderation tasks by username, such as your own, and it should show removed content.
I’ve found actual instance bans don’t federate reliably though, e.g i cant see any of my lemmy.ml bans on lemmy.one. so you’d have to check the target instances by opening their web page in an incognito or logged-out browser window, and view their modlog directly instead of your home instances’ modlog.