The WorkForce 3820 is an AirPrint printer that will work with your computer without any installed drivers by Epson. The first thing you need to do is verify that it is connected to Wifi. Epson provides these instructions for connecting to your WiFi network on Page 51:
https://files.support.epson.com/docid/cpd5/cpd58812.pdf
Once your printer has been verifies being connected to your WiFi Network, delete your current printer drivers listed under > System Settings > Printers & Scanners, then add your printer again. It will detect your printer and you should choose Bonjour/AirPrint as the driver under "Use" instead of the driver provided by Epson.
You should then be able to print to that printer and scanning is done by the Image Capture program that you will find in the Applications folder. Troubleshooting steps are the typical restarting the router, printer, and computer. I know that this may seem like nonsense, but does resolve many problems especially when dealing with network connections.