These are basic plug n play devices. Do these quick tests for functionality in order at the location of the Modem/Router. These tests require at least 2 of the ECB/WCB adapters.
Take both adapters, connect the Ethernet cable into both adapters Ethernet ports, take the coax cable and connect it to both adapters coax in/network port, connect both adapters power supplies.
See an image of a loop test
You should get all 3 lights on the MoCA adapters. If you do then do the next test, if not try different Ethernet or Coax cables then return units to store for replacements if still no lights.
Connect an Ethernet cable from modem/router to the first MoCA adapter then use a short coax cable between the coax in port on both adapters, then another Ethernet adapter to a laptop/desktop.
Power up the adapters and your computer should have internet access.
If both the above tests pass, then the issue will either be with the cabling between the 2 locations or the settings on the modem/router or the computer.