This forum is a great start.
You are tech savy enough for being here
I have found that planning a route is made alot easier by sharing reviews on sites like Yelp or Urban spoon for places to stay
Since you have a trailer you have a place to stay so Apps for Walmart parking,Next exit or camp grounds like KOA are great and the people who have stayed there can be your compass as to whether their experience was a good one or not
We did a Motorcycle tour through Chicago and google maps was a blessing,.
Not only could you plan your route but you could zoom right down to to Street View and see the condition of the neighborhood and roadway long before you ever left
ANsd as mention by other stick to populated area ,well lit and trust your sixth sense if anything doesnt feel right