In the beginning you do not need all the merchants onboarded. Is enough a single one (the smart one) that is willing to offer you anything you need for your sats. The small "mom&pop" shops are perfect for this. Will be like your "personal amazon shop".

I have a shop owner doing that for me for years now... he even offered to pay all my fiat bills in my name. Anything I want I order through his shop (is a small grocery store).

But the important part is not how to spend, nowadays we have so many places where to spend easily. The important part is to have a constant flow of sats into your wallets and do not depend anymore of fiat banks.