Rae from Shopify here. Thanks for reaching out about your PayPal setup, and welcome to the Shopify Community.
In order to connect a PayPal account to Shopify, we require that you have an existing PayPal account tied to the email address used to create your Shopify store, or another business account on PayPal.
If you have an existing PayPal account, please follow the steps here to change the email address tied to this PayPal account to match the email address attached to your account owner’s login on your Shopify store. This email address can be found in your Shopify admin by clicking on ‘Settings > Account’ and clicking on the account owner’s name. Or, to create a new PayPal business account to connect to your store, please follow these steps instead.
Once you make either of the above changes, your PayPal account should connect to Shopify and accept payments correctly. However, please make sure to test your PayPal account by following these steps to make sure it’s working as expected.
For more information on setting up PayPal, we also have a great help doc that explains all the steps needed. Check this out here.
Let me know if you run into any troubles with this set up and I’d be glad to help out further.