One tip I would give you to get you started is to use a “Modular Modeling” methodology to start these types of scenes:
Rather than build a house, build the modular parts - door, windows, crossbeams, roof sections, walls.
This way you can then re-use these components to make additional accompanying houses, sheds, barns, etc.
The best way is to start building a single building, and then step back from your modeling and look for ways to re-use parts, and/or separate parts into pieces that can be re-used. Almost all 3D software applications allow you to duplicate objects into “instances” (or similar names) that are data-tied copies to your original. Edit one, and all are edited. This way if you make a change to a window, all window copies are updated.
You can probably find some good tips to get you started from our friends at Polycount: