Hey so I probably have a great perspective for you since I'm brand new to total war and Warhammer as a whole, and I just beat my first campaign last night with the Empire, praise Sigmar.

Some notes I have. Even on easy difficulty you will come across a lot of adversity. If you lost a settlement early on, or take on too many wars at the same time you're going to have a bad time. You might not lose your entire region, but it will set you back enough where you won't be on equal footing when you starting coming up against your main antagonists.

This is based off my experience with the Empire specifically, so other factions mileages will vary obviously. Every faction is different, with most saying the Elves and the Empire are your best noob factions. Not that their specifically easier, just that their baseline mechanics are easier to learn. I could try to give you tips on how to make money really fast, but it's all additive, there's no one solution to financial woes. You can't sleep on diplomacy even when your trying to be a war-faring wrecking ball of doom. Trade agreements with other factions can be , sack settlements repeatedly, and disband weak units that weren't worth their rate after coming up with stronger units a lot. Early game you will always feel broke though, so build as many high tier settlements with roads, and docks. Giving them a tailors guild to start boosting your base economy which can always be dismantled and moved to your lesser settlements later, but don't skip out on growth either. It only takes three turns for the first tier of the clothier to make a return, so the sooner the better.

My advice is stick to a faction, and just keep hammering at the first few turns a few time until you have enough of an advantage to just roll through the rest of your campaign. Once you memorise the battles for the first few turns you can get a doomstack ready by turn 20 and start cleansing the world of your enemies. I won't lie, I save scummed a lot just to test the waters on a lot of mechanics, as the tutorials are pretty lacklustre. It was only after a few dozen hours it finally started to click. Which sounds long, but effectively you're learning two games with the campaign map and the actual battles having very little similarity in gameplay.