First start with just a couple of hardwoods from your area. Keeping it down to just a couple will not bog you down with too much to learn at one time. Find one that is living that you can identify easily, then go through the woods looking only for and identifying that specific tree. Look at the leaves, bark, and general structure shape. Look for young and old trees both, because the bark can look a little different on a 5 year old tree vs a 30 year old tree. Look at the dead branches on the tree and how the bark and tips look where the leaves would have been.Look at the color of the wood and how the grain looks under the dead bark. Keep looking and identifying for a couple of weeks until it is easy to spot one anytime you are around it. Then start looking for the dead trees of the same kind. usually there will be some dead ones around the living ones you identified earlier. Do this for a couple of weeks until it is easy to identify this specis dead or alive. Then go to another different tree and do the same. A favorite of mine from my area that not many people talk about is Dogwood. It burns super clean, is extreamly hard and makes a good bed of hot coals.The tree does not get very big, so most of the time the pieces you gather are small enough to use without splitting, and there are tons of dead dogwood trees around to be used.
Hope this helps and good luck.