The most often used information and regulatory marks show orange shapes on a white background. Isolated danger marks are installed on or above a hazard with water all around it, and are black with red bands. Two balls or spheres are suspended on top of the mark, and there may also be a flashing white light. Range lights and daymarks indicate a safe course. Your nautical chart will show whether the range indicates the center of the channel, and which section is safe to travel.
Ranges show rectangular dayboards, and the colors of the dayboards and range lights vary.
Safe water marks are red and white striped, with a red ball or sphere suspended at the top. They are yellow, and may carry a yellow light. The final test of your mastery of aids to navigation is being able to match what you see as symbols on a chart to what you see as markers on the water. That comes with experience and more time at the helm on unfamiliar waterways. Becoming familiar with all the various types of buoys and beacons will make you a better boater and a more confident skipper.