Wills

The only way you can get your questions answered, reliably, is by taking your will to a local attorney.  It is true, as you suspect, that the law of wills is not exactly the same in every state, and your concern is entirely appropriate.

There's a good chance that no changes will be necessary.  If changes are needed, it may well be possible do those with a short "codicil" that meets the North Carolina requirements, and effectively amends your Florida will.

If a Will was executed ac­­­­­­­­­cording to the laws of the state where you previously resided, then that Will is valid in your new state of residence.

However, even if your out-of-state Will is valid in the new state, it is impor­tant to have it reviewed. Also, your out-of-state Will may not be self-proving.  This would mean that at your death at least one witness would have to be located before the Will could be admitted to probate.  This can be an expensive and time-consuming proce­dure.  Additionally, there are restrictions on who can be named to serve as your Personal Representative. So if you will be living in NC, it is a good idea to have a Will that has been drawn up there. 

Note:  Even though the main probate administration would occur in your state of residence if, however, you own property in your own name in another state for either personal or investment use, you may be required to open a probate estate in that jurisdiction.  Again, consulting with an attorney on all of this is the best way to protect your rights and ensure a smooth administration of your estate.