Usa Driving Map I Can Read Maps But Do Not Understand Them. HELP! Can You Tell Me Where To Find Info On Driving In The USA?

I can read maps but do not understand them. HELP! Can you tell me where to find info on driving in the USA? - usa driving map

I'm going to America every summer, but it is usually a disaster. We rented a car and start our road trip. It would be helpful if I knew, understand how to read maps. I would like to know what traffic signs mean. For example, there are numbers like 875 and I-75. They said that I-95 will be like an adult in the United States, but we are confused when we see all the other figures. However, I must say that going with our limited knowledge that we have been able, from Florida to New Jersey. Also tell me how could we pass through Savannah, in North Carolina and elsewhere, and not go to Alabama and Tenneesee?