The complete method of how to build a drone is given in this app, you can make it at your home by looking at it.

The complete steps of how to make a drone are in this application, how much will it cost to make salmon and buy, how to fly a drone and precautions, you will get all the information here.

All parts and their functions
Motor, frame, speed controller, flight controller, transmitter, receiver, battery, petals etc.

You can use this application without internet also.