Where to start to make a Multiplayer Board Game?

Development Programming & Scripting
2

If you open your Unreal Launcher and click on “Learn” tab it will link you to a lot of tutorials,
you can always go straight to UE4 home page and click on “Learn”.

Here’s one:
A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums

Then check out the Networking:

And also check out content examples. Good Luck and have fun :)