how to set up email filter step by step

Have you done business with them before?  Since Bed, Bath and Beyond is a legitimate business, did you try just using the "unsubscribe" link?  Usually found at the bottom of an email.  Because there are a number of ways you can set up a filter depending on the conditions you want to use.  It would be something that is consistent from one email to the next. 

Or----------

Open one of the emails from them, and in the header click on the "hamburger" (three small horizontal lines) icon and you will get a menu.  The last item in it is the option to set up a rule for that email.  When you open that it will have the subject and sender already filled in for you.  Name the filter, add the action you want to execute, and save it.

Hi, @lusterav

Here is link that will show you how to create email filters:

https://comca.st/3OOEpru

How long before the filters I set up start working?

@user_a2fb40 

After you set up the filter and save it, it  should start working right away.  But I have found that you might need to then sign out of the account and back in again to get the filter to "take".