I just received command of my AFJROTC unit. Any tips or suggestions on being a competent detachment commander ?

Congratulations on your new position! Now remember that the two most important things in any leader's life are: Accomplishment of the mission, and welfare of your Soldiers. Your men will also respect you a lot more if you lead from the front, and by example always. If your guys are working, you're working. If you expect something of them, then you had best do it too.
Another thing you can do is encourage your subordinates to take initiative. Put them in charge every now and then, and do your very best to help them advance just like your leaders did for you.

Congrats on your new Command! Best I can say Sir, is be present, but don't micromanage. Lead from the front and rarely from behind the desk. That is the difference between someone in charge in the military vs. a CEO in a civilian organization. Learn those you lead. Know what makes them look forward to coming to work everyday. What makes them tick? Survey your troops, within the first 30 days and solicit confidential uncensored AAR comments on sustains and improves (with recommendations) on the organization as a whole. I am not talking command climate surveys either. Always remember the thoughts going on in your head right now and why you want to do this job. So, when things get tough, or you get that one knucklehead, just remember what your goals are and what this command means to you. Last, don't go into the job with the mindset that you are going to make changes immediately. Use your first few weeks in observation mode only. Then question why things are the way they are. Know who your SMEs are. Who does what great. Have those SMEs cross-train, so you don't have a single point of failure. Know what right actually looks like before you tell someone they are doing it wrong. Sorry, Just brain dumping the lessons learned for the best and worst new commanders I've had to work for. Best of luck Sir.

Congrats Oscar. The biggest thing you can do for your developing young men and women is to show them the possibilities they can achieve and how their lives are better for it. If you focus on others, your journey will take you to places you never would have dreamed either.