So you want to make some farms. Here are a few that I think are the best to build in Minecraft. Shout out to Shulkercraft who made all the videos you see in this list.
Carrot farm
It's not the greatest in terms of hunger or saturation but it is a good farm to start out with since they grow significantly faster than wheat and can be harvested automatically with the help of villagers. Plus if you craft them into golden carrots they are actually one of the best foods in the game saturation-wise.
Enderman Farm
You might be wondering what am I going to do with a bunch of ender pearls when I'll have an elytra? Neither do I, but Enderman farms are a really good mid to endgame farm to build. They give you insane amounts of XP even leveling you up to level 30 in under a minute! They can be a little scary to build but this video is really good at showing you how.
Villager Farm
Super versatile and powerful farm that can provide lots of things to your Minecraft world. From iron farms to enchantment villagers, it is a must in any Minecraft world.
Witch Farm
If you want to make potions in mass without the hassle, witch farms are crazy good. It does take a bit of work to find a hut and build but with a bit of time it is definitely worth it.
Iron Farm
Finally, the last item on our list, Iron farms. If you can get a hold of villagers, iron farms are super useful. For one you can make iron tools which are always handy, but they are also useful for more redstone-related builds like pistons and hoppers which can be extremely costly.