Who regulates what
In the United States the FAA regulates flight operations and airspace. The FCC regulates the radio spectrum your control and video links use. Local governments and land managers can also restrict takeoff and landing on the property they control, even where the airspace itself is open.
Rules change and vary by country, state, and locality. Everything here is an introduction; always verify the current official rules before you fly.
Recreational vs. Part 107
Flying purely for fun in the US falls under the recreational flyer rules, which include passing the free TRUST safety test and following a community-based safety framework. Anything that is not strictly recreational, including most work and paid content, requires the Part 107 Remote Pilot Certificate, earned by passing a knowledge test at an approved testing center.
Aircraft over 0.55 lb (250 g) generally must be registered. Most aircraft must also broadcast Remote ID, which transmits identification and location while flying.
Airspace and altitude
The general ceiling for small drone operations is 400 feet above ground level, with structure-based exceptions under Part 107. Controlled airspace near airports requires prior authorization, commonly obtained in near-real time through LAANC. Always check for temporary flight restrictions before you fly.
Crewed aircraft always have right of way. If one approaches, descend or land. Never fly near wildfires, disaster scenes, or emergency operations: drone activity grounds the aircraft that are saving lives.
Safe operating habits
Keep a clear takeoff and landing area, free of people, pets, vehicles, and loose debris. Brief anyone flying with you on roles, frequencies, boundaries, and what to do in an emergency. Wear eye protection around spinning props and during bench testing.
If someone walks toward your flying area, land or move the aircraft away first and talk second. If the aircraft does something you did not command, move it away from people and land as soon as it is safe. And never fly impaired.