To zoom in/out you can either use the pinch motion on your trackpad, click on the +/- icon or use the mouse scroll wheel.
For Mac users, to pan the map, hold down on the trackpad while moving your finger
For Windows users, left click and drag your finger on the trackpad
To toggle between Dataset and Site View, click on the building icon below the +/- icons. The red markers that appear mark the dataset locations. The icon in the center of the marker displays the dataset type.
Markers will cluster together as you zoom out, and spread apart as you zoom in. To zoom in to a specific cluster, simply click on it and the markers will spread out.