Quote from BioWizard >>

I don't know how your adventure is done map-wise, but outdoors, you usually use a hexagonal map, and each hex is a large area, say 6 miles. The party can travel about 24 miles per day, or about 4 hexes. Traditionally if you are having them travel through hexes in the wilderness there would be only a small chance per hex that anything dangerous happens. Usually no more than once per travel day.

However, that sort of travel is "out of fashion" these days (called the "hex crawl") and many DMs prefer to just do a "travel montage." You describe the process of getting where they are going, and maybe there is one encounter on the way to spice things up.

 I use hex maps for everything. it's not just for overland travel. I use hex maps for tactical fights because they are more intuitive. You can look for gaming paper and pick up a roll for a few bucks. You can draw on it and use coins or other counters to place characters and monsters.

The starter adventure should give you tips and advice built in. If something comes up during play that you're not sure of just wing it. It's better than stopping the game to look it up -unless it's something CORE like "how do I hit a monster?"

The main thing is that everybody (you included) have fun. The thing kids will appreciate most is that there are no walls. In video games, there are walls and limits, in RPGs there aren't any. It's OK for them to do silly stuff just warn them that doing stupid stuff has consequences.