Need checkout page design & developed for desktop & mobile version below points needs to keep in mind:
1) When we click on Sign in button then popup will be open and show facebook and google login functionality.
2) When we click on Login button then popup will be open and show username and password form for login.
3) When click on the specific Payment method then payment form will be show on the popup.
4) Payment method will be Stripe and for other payment method, we will tell.