I'l just add this to Omicron's post.
It's not just the realistic agriculture aspect that is changed. it's everything.
you want a pickaxe? well i got news for you. you first have to smelt ore in a bloomery, and let it solidify into a clay mold, then you have to hammer the solidified metal into a ingot proper on an anvil.
Only then, can you make a plan. (needs paper, ink, and a scribing table). put it in an anvil,, then you have to heat the ingot up in a forge til it's hot enough to work, but still cold enough not to melt. and hammer it into shape on the anvil again. Just like a real life ancient smith. The minigames alone require a load of skills to master, and it takes a lot of time as well. you aren't going to be digging into the earth for ores on your first day. probably not even your first week. you will be too busy trying to just stay alive.
Without proper equipment however you won't be long for this world. with the massive solidness of the worldgen, where caves are actually rather rare compared to vanilla, you will be swarmed by mobs if you camp without a protective berm of some kind or other... except.. gravity affects blocks. all blocks. making a berm actually takes a significant amount of work. luckily you can find t0 metals on the surface by picking up rocks.