I was not aware that the NLC included CNAs, and I have no idea how CNA certification works in MD, but I can explain the NLC (Nurse Licensure Compact).
The compact works exactly the same as your driver's license. Everyone understands easily that you have a driver's license from your home state, and you can use that license to drive as far as you want, for as long as you want, anywhere else in the US -- as long as you still live in your home state. If you move to another state, you have 30 days (or whatever the state law says) to get a driver's license in your new state. The only reason it works that way, and you don't have to stop and apply for a new driver's license at each state line when you're on vacation, is because long, long ago, back at the dawn of the Automobile Age, all the US states got together and signed a compact (like a treaty, an actual physical document) agreeing to temporarily recognize each other's driver's licenses for travel purposes.
The NLC works exactly the same way, except that not all states have chosen to sign (join) the compact so far (only about half the states are members, I think). If you live in a "compact state," your nursing license will be recognized/accepted for work purposes by every other compact state. You can work in another compact state for as long as you want, as long as you maintain your permanent residence in your home state. If you move to another state, one of two things will happen. If you move to a state that is not a compact member, your "old" license will remain valid for your "old" home state (until its expiration date, that is -- and you can choose at that time to renew it or let it lapse), but it will lose its compact privileges and become just a regular, traditional license -- it will only be good in your old state (not in any other compact states). If you move to another compact state, you will have to apply for a new license in your new home state, and your old license will become invalid in 30 days (you can only hold one compact state license at a time).
It's also important to be aware that, when you are using your "home" license to practice in another state, you are bound by the NPA of that state while you're working there, and it's your responsibility to be aware of any differences there may be between what's permitted in your home state and what's permitted in the state in which you're working.
There is a lot of talk now about the NLC and compact states and compact licenses, but the NLC really matters only to a small group of nurses -- mostly those who either 1) do travel nursing (and maintain a permanent home in a compact state) or 2) live close (close enough to commute for work) to the border of two or more compact states -- f'rinstance, I live on the border of my state and work in the nearest city in the state "next door" (both compact states). For the vast majority of US nurses, the NLC is never going to have any impact at all.
Best wishes for your studies!