I see you already have your options, take a look at this list of The Best Payment Gateways for Shopify here.
So it can help you to have an overview of Shopify Payment, Paypal, Stripe, and many more that you can make the right decision.
Nick here from Shopify. First off, I want to say congratulations on starting a store and best of luck with it going forward!
Great question regarding what payment gateway you can use. If you are based in the USA which you hinted at, Shopify Payments is available to you and could be the best option. You can learn more about Shopify Payments and the benefits of using it from the help guide Shopify has for it here. Shopify Payments is the simplest way to accept payments online. It eliminates the hassle of setting up a third-party payment provider or merchant account and having to enter the credentials into Shopify. With Shopify Payments you're automatically set up to accept all major payment methods as soon as you create your Shopify store.
If you wanted to explore some third party payment providers, you can see the third-party gateways Shopify is partnered with here. I can't say which is the best fit for your business and store, so it might be worth your time to take a look into them all and see what might work for you.
Let me know if you have any other questions about this or anything else though!