Help with beginner players

Okay, I need some help. My in person group is more or less made up of beginners. I've run LMoP with them, and it went terribly. Sure, they did run the first two chapters with a terrible DM (I'll provide details if asked), but they literally cheated by reading the book at home. Anyways, I'm planning on running a homebrew campaign and I need help with a few things.

1. Helping my players make characters, not blank faceless puppets which live for the sole purpose of doing what they think they're "supposed" to do.

2. Helping my characters not be so selfish and try to make themselves the most powerful of the group, even at the cost of others

3. Teaching them how to roleplay.

4. Getting one specific player to stop approaching me with ridiculously unbalanced homebrew.

And no, I'm not going to get a new in person group if that's a suggestion.

1) Each player should work out the answer to only a few simple questions about their character. A good set of questions can be found at: see https://www.greatgamemaster.com/dm/player-character/2021/crafting-a-strong-rpg-character-backstory-5-questions-to-consider/

2) Missing from the above is the question of why are the PCs adventuring together? How do they know each other?

3) Ask them to describe their PCs actions (ensure that you give equal time to each player as you go around the table).

4) Set some basic character creation rules, such as PHB only - no homebrew. The only allowed homebrew in the entire campaign should be items that YOU (the DM) have created.

Okay, thanks for the advice! That will probably help.

"D&D is not like a video game. It's more like improvisational-theater. You and I are working together to write a story, with you being the protagonists (stress the plural) and I being the narrator. The goal isn't to "beat" some arbitrary imaginary monster, but to feel and to care about the characters, world, and story that we have built together. The game exists solely to give consequences to actions, to give depth and meaning, to allow us to care about the story, and nothing more."

- Me

Is this because they're new, or because your expectations of the game are different? If they want to hack n slash through a dungeon and collect powerful items, while you want to roleplay intrigue & emotional weight, you might just not mesh up. I'd start by asking what kind of game they want to play, if you haven't already talked about it. Like Iera said, a session 0 is very important when establishing a game.  

Quote from VanZoeren >>

Is this because they're new, or because your expectations of the game are different? If they want to hack n slash through a dungeon and collect powerful items, while you want to roleplay intrigue & emotional weight, you might just not mesh up. I'd start by asking what kind of game they want to play, if you haven't already talked about it. Like Iera said, a session 0 is very important when establishing a game.  

 Fair. I'm thinking that it's probably because they're new.