How does someone just decide to be a farmer are there classes or do you have to grow up on a farm? how do you acquire the land etc?
Usually it's a family thing.
You don't need land really. Just put on overalls, tuck your thumbs in your armpits and walk around while saying, "sure could use some rain"
Boom, you're a farmer.
You must live near me
Depends on what type of farmer you are (plant, livestock, other), but basically farmers simply grow stuff... so have all the resources to grow stuff and suddenly you're a farmer. (Maybe not legally, as legally different areas you sometimes have to prove it in different ways for tax breaks and other type things).
I also want to add...
Have all the resources and grow stuff is how one can become a farmer, BUT to become a GOOD farmer is a different story, that takes knowledge, effect, hard work and some love.
Over here you can do a college degree in Agriculture at a specialised Ag college, but most just have parents who own a farm.
Grow something and sell it.
If you aren't born into it, it's almost impossible these days, unless you have a lot of capital. The land is generally more expensive than the profit you will make from it as a "startup". (It CAN be done, it's just really tough)
He plants a seed and calls it a farm.
It ain't simple. I've been trying for twenty years. Got pretty good at being a gardener though.