This list is in no particular order, but is more of a checklist of things that you need to know if you want to be a professional wrestler,
1) You are a nobody to 99.9% of wrestling fans. Those are the people that follow the sport. To non-fans, you are probably a guy on steroids who puts on underwear and rolls around with other men. If you try to pick up girls by saying you are a wrestler, you are a douche. If you are a star, you do not have to tell anyone.
2) Respect yourself, because no one else will. Just because you have the opportunity to work everywhere, doesn't mean you should. There is not a shortage of wrestlers. Any spot you have can easily be taken by someone hungrier, cheaper, younger, healthier, dumber, and less talented. Stay motivated, do your best every time, and make everyone around you better.
3) If you have a significant other that you want to bring into the business, understand that they will soon no longer be your significant other. You will be mocked for this, and deservedly so. If you are going to have a relationship with someone in the business, keep it under wraps - your personal life is no one's business.
4) Work as much as you can, in as many promotions as you can - just not all in the same area. Traveling to different places and to different promotions means you will learn more, from more people, and you will become more well-rounded as a worker. Staying in the same area and working for everyone in that area doesn't help you.
5) It is important to get as much work as possible. When you get to the point when you have a full schedule, and people ask you to work for them, that is when you can start to worry about the monetary part of the equation. Until you can turn yourself into a sought-after commodity, you have no leverage for money. Get as much ring time as you can, get as many bookings as you can, and make people want to book you. Until then, you have to settle for whatever you get.
6) Keep your eyes open. Keep your ears open. Keep your mouth shut. 99% of the time, getting a break of any kind depends on who you know (and who they know), and not your ability. Get to know everyone, but make few friends and fewer enemies. Remember everything you see and hear, as this is how you learn.
7) Wrestling is first and foremost a business. It is not a social club. Sure, there is a brotherhood and camaraderie among the boys, but the purpose of the cards and working the matches is to make money - even if it is only so that the doors can stay open and you can continue to wrestle. Never treat it as a hobby, or something to do for kicks. Be passionate about it.
8) If you have dreams of making it to the WWE, take a long hard look at yourself. Are you well over 6ft tall, and a bodybuilder-esque 225lbs? Do you have a minimal amount of body modifications? If you said no, then you will never work for the WWE. Sure, you can point at examples to the contrary, but they bring something to the table that makes the WWE look beyond their standard requirements. If you want to work for the WWE, work on that.
9) There is a difference in how you wrestle in front of 10 fans and 1000 fans. It is not a difference in effort, it is a difference in stupidity.
10) Wrestling is not fake. When people outside of the business ask you about how wrestling works, you do not need to discuss it with them. Chances are, they are just going to mock you for what you do. If they have an interest and respect for what you do, they will not ask you if it is fake.
11) You do not ever have a "permanent position". Every regular booking you take will end at some point with you getting fired or quitting. If you go in knowing this, you will have less stress. Just always do your best to make as much money and perform as best you can for as long as you can.
12) You will get injured. Bad. If you cannot handle that, quit wrestling. If your loved ones cannot handle that, you need to help them understand, or deal with it. Everyone gets hurt. You will not be cut any slack because you fear getting hurt.
13) Always protect who you are working against at all costs. Your goal should always be to make sure the people you are working with can go home and play with their kids after the match.
14) People that take liberties in the ring are not professional. Anyone can take advantage of someone who is presenting their body with the understanding that you will do your best to not injure them. Wrestling is a business about making money and good matches. You do not have to like someone personally to act professional in the ring with them.
15) Always work the crowd. The fans sitting at ringside paid to see you wrestle. Chances are that you will be paid from the crowd drawn at the gate. Until video brings in enough money to pay your booking fee, work the crowd.
16) Dress like you are a wrestler. That means proper combat gear. Trunks, MMA shorts, full-leg tights, singlets, boots. Not jeans, t-shirts, sweatpants, etc. The only exception is that there should be very few exceptions.
17) Workout. You need to look like a fighter. You need to look like an athlete. You should be training, working out, and conditioning yourself regularly. You should never think that wrestling on shows is your exercise.
18) When you enter the lockerroom, make an effort to greet everyone with a handshake. "Everyone" includes the non-wrestlers (referees, managers, trainees, and especially the promoter & staff) as well. Introduce yourself to people you do not know with the name you prefer to be called. Make the same effort to say goodbye as you leave.
19) People that pay for tickets are what keeps wrestling alive. Be respectful of fans, regardless if you are a rulebreaker or a fan favorite. Fans do not have the right to cross certain barriers, and neither do you.
More to come as I think of them...