Go to merchants in your neiborhood and talk to them about Bitcoin and LN. Show one transaction and how fast It works. If each person envolves your neiborhood, in few time all the city will acept Bitcoin as payment option. Good Luck.
Discussion
What PoS system are you recommending? BTCPayServer? Breez? Bolt Card PoS? Square? Something else?
Are you training in person or providing an LMS for merchant staff?
How many times does a merchant need to be visited before they adopt Bitcoin or not?
For PoS we use Coinos (easy to understand and use). About training most of them are in person, but you can schedule a presentation to local merchant association.