new to this game genre, and i have played a little, but it feel hard to see what the different things do......
As I was an avid Dungeon Keeper and Dungeon Keeper 2 player ever since these games came out, WFTO felt very familiar to me right from the start.
I found a few guides and beginner tips hore: Multiplayer Strategy Guide (in the Brightrock Games forum)
There are two PDFs linked in this forum comment: Beginner's Guide (Steam Discussions) More advanced strategy guide (Brightrock Games Forum)
You might also find even more information in the WFTO Subreddit
And here are two YouTube videos that I could find without digging too deeply: How to improve your playstyle - Basics War for the Overworld #Tips&Tricks - Patch Review v1.0.11 - v1.0.18
I hope some of that stuff is helpful for you.
By the way... have you already read the 45 pages long Dungeoneers Guide to the Underworld
PDF that comes with the game? It may contain a lot of valuable information for beginners about every single unit that exists in the game.