Beginners build orders to master first?

One day I woke up and decided to be a pro aoe2 gamer. Never knew what was waiting for me so I started researching and watching guide videos.

Now I just want to have fun and learn enough to be able to play fun ranked games.

I realized that I need to memorize build orders so I started with fast castle. The problem is there are hundreds of different builds named fast castle with different orders. In my first research I memorized the standard start; 6 on sheep, 4 on wood, next to boar, 4 on berry etc. some fast castle build start this way and for example one build sends 5 on berry instead of 4. I got lost a bit and I need your help to get a solid beginner build orders to memorize.

I really suck at units too. Never know what unit to go with. With fast castle I guess the main unit is knight but am I gonna need other units and what are they need to be.

Open for any help and information :)

I am working on my hotkey skills btw :)