Both receivers have their antenna under open sky? The base has had enough time to obtain base location (not sure how ardusimple have configured the survey time)?
I don’t think I had to configure anything in mine either. Make sure you are using correct rtk2b and radio for rover. Should be labeled. Other than that, set up far away from trees or buildings. U center is the software you need on laptop to configure. When you connect to rover, it will tell you more info. Makes troubleshooting much easier. Shouldn’t have gps if wrong baud rate, but I would double check that on u center as well.