Spatial and traffic picture
Reading a small plan view: which aircraft is closest to the centre, which is highest, which pair is closing, and which pair will be inside 3 nautical miles and 1,000 feet if nobody turns. North is up. Altitude is in feet, shown on the label as flight level hundreds.
How to read the scope
The centre is the field. Rings are only a scale. The line on each target is its heading, not a history trail. The number after the callsign is the altitude in hundreds of feet, so 120 is 12,000 feet. The free drill does not move the targets: you are judging the picture you were given. Paid drills ask about motion: a closing pair, or a pair that will lose separation inside two minutes.
Answer the question that is written, not the aircraft that looks busiest. Keys 1 to 4 pick an answer. If two targets look close, use the altitude. A pair 2 miles apart and 4,000 feet apart is not a conflict under this rule.