Usually, you would start off with the Landscape and then add in the Road…or integrate a road with the landscape…
You can activate the ANT landscape generator that is included with Blender…or it could be a procedural terrain…( I would stick to ANT for now!)
Far too many steps to get a road on a landscape in this thread…so watch this one…a bit more complicated than others but the finished product is very nice… and it would make your work so far usable instead from starting from scratch…