Where to start
If this is your first visit, start with the natal chart. Almost every other tool needs it: transits, synastry, astrocartography and the forecasts all draw on it. Enter the data once, save the chart, and it fills in automatically from then on.
All calculations run in your browser through Swiss Ephemeris, the same library professional astrological software is built on. Planetary positions are accurate to the arcsecond, house cusps to the arcminute.