If you're hoping to remove Google Pay, then you'll want to toggle the feature off within the Shopify Payment settings. This can be done by navigating to Settings/Payment Providers and selecting "edit" for Shopify Payments:
If you wish to only offer Paypal, then you would want to disable Shopify Payments by selecting "Deactivate" after selecting "edit." Doing this will mean that your account will be subject to transaction fees per order which would be on top of the fees that Paypal charges you.
If there's anything else I can help with please don't hesitate to reply back and I'll happily help out!
I am trying to remove google pay as an option in the way described above because we have not set up our merchant services yet. It will not let me only remove that because we are not eligible (because merchant services are not set up) but when I try removing all options under shopify payments it says I must select one. We are using a 3rd party payment method for now until we get that set up so I would really like to have it removed. It appears on the cart page but we do not want our customers using it yet. Please help