Difference in levels is very simple.
Level 1. Don't be alone in the locker room with little boys I don't sleep with their moms. The black thing is called a puck. Cross ice, cross ice, more cross ice. A little kid being on a regular size rank is really bad.
Level 2. Don't swear in front of the kids. They show you how to keep score. Cones are used to help at practice and drills. Cross ice, small games, get three or four teams on the ice to maximize profits for the owners.
Level 3. Writing your thoughts down on a piece of paper or buying Mike Sullivan's flexxcoach for $100 a year is better than not having a plan for practice. Kids go through puberty. Concussions happen. Don't put a player back on the ice after he just got knocked out. Keep kids playing as long as possible so USA hockey can collect the fees.
Level 4. Level 3 repeated except they make you go away for a weekend in charge you $250. Lots of blowhards yammering on. Tons of tool coaches you are forced to hang out with.
Level 5. Vegas baby. Boobs. Don't tell your wife what you really did.
I've been with 3 orgs with 2 different kids, 2 fed and 1 bhl, coaching in both the Fed was the only org that required all the proper USA hockey crap, just no helmet that was up to us.