Trying to enable Stripe in Woocommerce

Hello all,

I'm trying to set up an SSL certificate so I can enable eCommerce directly on my site, and I have downloaded and installed Stripe. I can see the plugin is active, but when I go into Woocommerce Settings/Checkout, it is not listed as an option to enable. I do see in the Gateway Display Order a gateway called Credit Card but the gateway ID is Simply_Commerce, which appears to be created by Mastercard. Not sure how it got there, but I can't see how to disable or remove it. Is there a possibility that Woocommerce will not allow more than one credit card gateway? thanks!