By the way, I can recommend the habit of deleting at least one account per week.

Just look through your password manager, or the list of passwords kept by your browser.

Step 1: check if the site still exists and if you can log in (if not, delete the entry)

Step 2: look around and see what data they kept on you, for who knows how many years. You should now experience an urge for step (3).

Step 3: figure out how to delete the account. Often hidden under privacy or advanced options, more often requires an email to support. If so, set a reminder to followup after a week or so if nothing happened.

Step 4: once the account is gone, delete the entry from your password manager (browser)

Keep this up for a few years and you might get there....