Thanks for answering the questions, we have all we need now to tell you the rules you must follow, as well as some important things you should also follow.
Your Results:
You said...
Your drone is over 250g, but under 2kg.
You don't hold a current A2 Certificate of Competency.
You are not a member of a model flying association.
YOU MUST
Display a UK Civil Aviation Authority 'OPERATOR ID' on the body of the drone.
Hold a valid UK Civil Aviation Authority 'FLYER ID'.
Fly within visual line of sight of yourself at all times.
NOT fly higher than 400ft from the nearest point of terrain.
NOT fly within 150m horizontally of any residential, commercial, industrial, or, recreational areas.
NOT fly within 50m horizontally of uninvolved people (the public).
NOT fly over uninvolved people at any height (especially crowds).
NOT fly in a manner that recklessly or negligently endangers people or property.
NOT fly in a manner that recklessly or negligently endangers an aircraft, or any person in an aircraft.
NOT fly in a Flight Restriction Zone without appropriate permission.
NOT fly too close to people as to cause a nuisance.
NOT take off and fly from an area that does not allow drones.
YOU MAY
Fly using First Person View (FPV), but only when accompanied by a competent observer who is stood with you and maintains visual line of sight on your behalf.
Fly for commercial purposes, but ONLY when holding insurance that meets EC785/2004.
YOU SHOULD
Consider 3rd party public liability insurance.
Always practice in a safe area away from uninvolved people and property.