This support article covers how to turn your payment gateways into live and test mode.

What is test mode used for?
Test mode on a payment gateway allows you to test the process of checking out in your Storefront and Back Office without truly charging a credit card. Test modes for both Stripe and Authorize.net are handy features that ensure your gateway is properly configured as well before you officially "go live".

Where are the test mode settings found in Lead Commerce?

Test Cards
Stripe and Authorize.net offer test cards that can be used when in test mode. Here is a link to those cards:

Stripe
Stripe Test Cards

Authorize.net
Authorize.net Test Cards