One Page Product USA or Canada

I am currently selling in 3 countries. I average 150-250 sales a month but the payment is done on hand. I advertise on facebook and so far I have spent around 12,000$ for ads in 4 or so years. I get orders via messages, I send the products via a courier service and after the product is delivered I get paid. Usually takes 7-10 days for the product to be delivered and the money to come to me.

Now, I want to try a one page product (which worked for me here) but in the USA or Canada and try to sell there.
Any experiences? What website do you recommend for a store? Shopify? Payment method? PayPal is not allowed here.