1. Do not let them stick you on salary.

Salary to you means you get paid the same (sans bonuses) no matter how much you work. It means the same to the owners. This means they will expect you to be there all the time working ridiculous hours. I know one excellent chef in particular who did the math and realized the dishwashers were making more than him if you divide his pay/hours.

2. Friends before may not be friends after.

It's easy to be friends with people when you're on the line but if they're not very good employees at some point you will have to exercise your authority.

3. Be direct and clear. You're there to do a job, if it doesn't get done right you're the first person the owners will complain to. Remember it's a kitchen not a kindergarten, you're not there to nurture and respect feelings. Be clear and straightforward with what you expect.

4. If people do a good job tell them.

This is surprisingly often overlooked. Simply put if someone works hard and is doing a great job (or improving) tell them they did a good job and maybe get them a beer on the rare occasion. Don't do it all the time though or egos might start to clash.

5. Be weary of venders/suppliers.

Their job is to unload products on you. Some of them will see a guy who's new to the job and try to sell you on overpriced products you don't need or will try to dump less than fresh produce on you. Check all your deliveries and don't sign off until you're satisfied. Send stuff back that is no good, it pisses them off but teaches them not to try these games with you. Once suppliers know you're thorough and they can't sneak rotting lettuce passed you they won't try as often.

6. Deals, Deals, Deals

So you're in charge of food cost and specials, many KM's/Exec Chefs get bonuses based on food cost/labor cost so your goal is to minimize these things without hurting the food quality. Cultivate good relationships with your suppliers/venders always ask them what's in season with them and when deliveries come ask if they have any deals (sometimes you'll get deals like such as seasonal produce like berries they're trying to get rid of quick or say some fish accidentally got frozen overnight by their refrigeration unit but is otherwise fine.) Produce suppliers are always looking to get rid of something and you can get some insane discounts just to recoup something. If you know what you're doing you can make a killing on specials or cut the cost of a regular dish with no comparable difference in quality. Also soups, soups, soups these are money generating powerhouses that cost next to nothing to make.

7. Equipment breaks.

Don't freak out, just get through service and call your repair person.

Hopefully you'll find some of this useful. I was the same age when I took my first KM job also at a pub with a third floor just for events/banquets and can say pubs are a great place to start the management learning curve since half the customers are drunk.

Good luck and have fun!