how to get started as a merchant accepting coins?

I want to help my friend’s shop to start accepting crypto payments, where do I start? Essentially, all I need is just print out the QR code for each coin that he can accept but how can I get notification that it has been accepted. I don’t think we want to go the bitpay route since there’re fees associated with it. He’s not tech savvy at all and I think it will be a hassle for him to check the blockchain explorer. Also, where can I post that his shop is accepting coins so people can find him?