You can cast sorceries only during your main phases when the stack is empty and you have priority, not anytime during your turn.
The turn is divided this way :
Beginning Phase
Untap Step
Upkeep Step
Draw Step
Main Phase
Combat Phase
Beginning of Combat Step
Declare Attackers Step
Declare Blockers Step
Combat Damage Step
End of Combat Step
Main Phase
Ending Phase
End Step
Cleanup Step
I know the stages. It's the details I can't read online in tutorials (I have read many of them) I am missing. I know when I can cast a sorcery, but no where does it say how many (someone else has answered that here now, but that is just one example of how the online tutorials are lacking and why I am coming here asking questions). That's the problem with all the tutorials online, they list steps like you just did, with no details as to what actually happens in those steps. Here's an example:
"Main Phase: Most of the game's actions happen during the main phase. With the exception of Instants, cards can only be played during a player's main phase. There are two main phases each turn: one before and one after the combat phase."
Yeah, but it says absolutely nothing about the order you play inside that phase, how many cards you can play, etc. Never in any of the tutorials I have read so far did it say "Main Phase 1 (pre-combat), if you have sorceries you want to cast, do this FIRST, you may cast as many as you can afford, you will not be able to cast sorceries after you play creatures or instants."
It's like teaching someone how to make pudding like this:
Kitchen
Milk
Vanilla
Cocoa
Sugar
Cornstarch
Stove
Done
I don't know how anyone manages to learn the game using the tutorials given outside of coming to a forum like this and asking for further clarification (so I'm really glad forums like this actually exist). If anyone has a link to a detailed tutorial/rulebook/guide, please do share the link.
There is no order within the main phase. During a phase or a step, the first thing that happens is obligatory actions (such as untapping permanent at the beginning of the untap step). Then any abilities that triggers at the beginning of XXXX phase go on the stack. Then, if you get priority in this step/phase, you get priority.
The only limit to the number of something, is that (if nothing says otherwise) you can play only one land during your turn. You can cast as many spells and activate as many abilities as you want (or are able to).