Hi,
In your checkout options you have to use the steps "login - address - payment - shipping", and in the options below disable the login, set the checkout for guest users only.
By this way in the checkout there will only be the address asked, then select the payment method, the shipping one and the user is redirected to PayPal.
If you have only one shipping and payment method enabled, you can enable the option to select the payment and shipping by default. Then with some css properties hide the desired parts, like that the customer will only see the address fields, and the finish button.