Even with 2000+ hours in when it began, Alpha 18 was still a huge PITA when I started it. 18 is harder, especially since zombies are apparently bullet sponge psychic architects who can tear through steel with ridiculous ease. I wouldn't recommend normal difficulty for anyone who hasn't played this a lot or is playing with someone who has played a lot and helps them understand what's happening.
So with 2000+ hours in the game you're telling, that A18 was difficult on normal difficulty?
So either you didn't get how the game works or you just complain that the gameplay has changed somehow with A18.
A tip that may help you and your less experienced friends, raid POIs and get the loot. Don't use guns at the beginning, you should be able to kite the zombies with bows or melee when you first start looting. Save the ammo you get from the loot piles for horde night. Use different weapons so you can split the ammo. Even with 4 of you, your first 2 horde nights shouldn't be that hard on default if you aren't wasting ammo.
Use a mix of everything. Especially if you are looting, kiting Zs around and killing them with cotton balls (nothing else are the beginner bows with stone arrows) costs far to much time. Use a bow for the first shot, maybe second. If you have ammunition use them to kill them faster and therefore progress way quicker.
The first one to two bloodmoons can be easily survived by either choosing a robust building (with no way up) and just letting them hit everything and/or putting up spikes. Especially if you progress slower because you are a beginner, bloodmoons won't escalate quickly. They consist of few and low level Zs.
Without knowing anything the game may seem unbeatable but just knowing that Zs can't jump higher then 2 blocks (excluding spider Zs, but they don't appear that early) is all you need to know about how to setup a base for the first few nights or even the first bloodmoon.
Or to tell it different: Zombies can't do anything you are also not able to do. If you can't jump across 4 blocks, zombies can't do it either. Use that information.
If spider zombies occur, you will notice the exception, but there won't spawn dozens of spider zombies out of nothing, so you should be able to deal with 1-2 of them surprising you.
Difficulty is somehow even broken. We are playing on completely random bloodmoon and recently a bloodmoon somehow surprised us, there was no thunder until 21:00 and we were both inside buildings so didn't see the sky turning red. Because of that we had to spend the bloodmoon by driving around on our motorcycles... well we thought we have to do that. However driving around seems not to make the Zs respawn but you can quickly drive that far away that the Zs won't find you anymore. Result: I started harvesting car wrecks, looting garbage and birds nets. DURING BLOODMOON!