Agree with CAPT MJ's wise words. Best advice I have for a parent is to start "distancing" but be available. Once your newly commissioned ENS/2nd LT gets to his/her first duty station (being stashed at USNA doesn't count in my book), s/he will be responsible for everything. That means showing up to required evolutions (e.g., training, class, etc.) on time every time. Doing assigned coursework. Renting/buying a place -- and/or finding roommates. Paying bills. Getting insurance. Getting laundry/dry cleaning done on time. Having car serviced. Dating (and making time for it). IOW, being an adult.
You as a parent can't really help them through this. We all have to learn it at some point -- I guarantee you did and probably without nearly as much help from your parent(s) as you think your kid needs. You really can't make it easier for them and you definitely can't do it for them.
They will make mistakes. They will learn from those mistakes. You can't prevent that and, at a certain level, don't want to. It's painful to watch, but something that we all go through and, ultimately, makes us stronger, wiser and more resilient.
What is useful is to make occasional, sage suggestions that young people may not even have thought about (i.e., getting renter's insurance when your kid doesn't want to pay the $30 a month (or whatever it costs), getting professional financial advice early in life). And being available when they do have questions or do need your help (i.e., what to consider when buying a first home).
I would do take the same approach for 1/C year. Service assignment is really their first "adult" decision process (well, after deciding to attend USNA). Tell them, "We/I know you've got this. If you want to ping ideas off anyone, I/we are always here."