I think you need to give the country, as the infrastructure in a rural area varies widely.
In Britain every road is for cars, and in rural areas they can travel at 80km/h on them. There will be footpaths within a village, but not necessarily on the roads between villages. Cycling on footpaths is illegal, including for teenagers.
Other countries (Netherlands, Denmark, probably more) can have roads only for use by residents or farmers plus cyclists/pedestrians (e.g. gates at each end), or roads with much lower speed limits, or guaranteed footpaths. I've visited but not lived in a rural area like this, so I'm not sure how well it works in practise.
