Katy here from Shopify. Congrats on your first post, and welcome to the community. ?
With the Shopify platform, you will need a credit card to pay for your monthly invoice, however you can indeed accept payments from your customers using PayPal, or your preferred payment gateway, specific to your own location. This is totally possible to do.
In terms of arranging a payment method with suppliers, generally speaking this would be best answered by the supplier that you plan to work with directly. In some cases, suppliers may accept Payoneer as a form of payment, though this depends on their own services and set up.
Perhaps if you link a supplier you had been interested in using, some of our community members can comment based on their own experience?
I hope this helps you out!