RideWithGPS is a good free source of routes other people have posted and you might find some where you want to ride - and many people mention rest stops. MapMyRide is another one but I've found RideWithGPS has more coverage.
If you signup for the pay version of Strava, it has a cool feature: you can have it plan a route for two points and it will choose the roads most often use by all those other Strava riders who upload every ride they do. Not perfect - many of those Strava riders are trying to be the "King of the Mountain" and have the fastest time up local hills. But, I used it to plan a 3 day ride in Florida and it worked pretty well.
On the support side, if it is a major worry you can pay for a years worth of AAA, the auto emergency service - that covers you when cycling, too.
Personally, most of my rides are local and I have my wife and friends for emergency backup but I've done many without backup and just chanced it - as long as you are prepared to deal with one or more flats, rarely an issue. Broken spokes aren't that bad, you can release the brake (if you have rim brakes) and soldier on. I've only had one issue in many, many years - the seat clamp bolt broke on my then 20 year old Trek 520 when I was 10 miles from my car - had to bike back standing up!