I have a wsdl, a .pfx certificate file, and a keystore password. How do I enter these into SoapUI?

If you only need to make an SSL connection with your client certificate, have a look here:

https://www.soapui.org/getting-started/soapui-interface/preferences-and-settings.html#SSL-Settings

If you need to set up WS-Security, see the following:

https://www.soapui.org/soapui-projects/ws-security.html

If you need anything else, please describe more in detail what are you looking for.