Become a pilot for an airline company.
Become a steward on an airline.
These are easy ways to see the country.
Other ways include a little bit of training… and sales lol.

customer service, sales, many people do not like leaving home often or for long periods. if your willing to travel sales and service are the best. also you can drive RV,s or cars for people across the country. special delivery and personal currier services. all are good ways to see the country.
i know peole that drive boats from michigan to florida
and other places and make a very good living. I know people that just drive cars people have had to leave behind gor one reason or a nother. also insurnace companies us lots peopl that ned to travel at a moments notice to areas hit by storms,
and other desasters.

goood luck

Become a sales rep for a company, going to retail stores to promote their products. Many of these companies have regional offices, or you could travel all over if it's required. My friend's boyfriend used to be a sales rep for Vans, and now works as a sales rep for Zoo York, and he travels all over the East coast. I have sales reps coming into my framing store to show me new corner samples and promote their company's products. They travel all over the state, and there are trade shows that they go to all over the country. If you're good, you make a great living, too, but it's a LOT of time out on the road.

Flight attendant!
You get discounts on flights, too.