@2538 Welcome. Where did you download your app — to your phone? If so, you’ll need to create an account with Square, which I assume you have done and that it has been verified and approved. Otherwise, to accept payments you’ll need a card reader of some kind, unless you don’t mind manually keying card information. Just keep in mind that manual card payments cost you more than the ones you process through one of Square’s readers.
If you have a Square account, card readers can be found here — https://squareup.com/dashboard/account/reader-request
Or, if your account is not set up yet, go here — https://squareup.com/us/en/hardware
Let us know if you have any other questions. I, or another Square seller, can help you out.
Best,
