Western astrology cannot predict with 100% accuracy when you will get married, have a child, predict the lottery. Horary astrology can however answer questions like this, but NOT natal astrology....

Amongst other things, astrology is a wonderful tool for understanding yourself and others better.....enabling us to make better choices in life as we become aware of how our behaviour influences what happens to us through the law of cause and effect. Astrology does not reliably predict the future.......But it can provide an excellent insight into the psychological make-up of people, enabling us to accurately predict their behaviour and it's resultant effects

If you intend to learn about astrology, you will need to begin with a natal chart, it need not necessarily be your own, but many choose to begin this way, in an effort to better understand their own life journey, and purpose. Astrological natal charts are as individual as a persons ‘fingerprints’ depending on where (latitude & longitude) and time of birth. It is important to get your *time of your birth* as this is the most important information.

In the beginning of Liz Greene's (famous prolific author on astrology), “Astrology for Lover's” book there is a good chapter on What astrology can and can't do.
“Astrology is baffling because it works. So, what in fact is a horoscope?
What it's not is a way of foretelling the future, or of determining whether that tall dark stranger will turn up next week. To put it briefly the horoscope is a map of the psyche of the individual. it's a kind of blueprint, a seed plan, a model of the energies and drives which make up a person. Because it's calculated precisely for time and place, it's unique, unlike the sun sign column. Even identical twins are born at least four minutes apart, and in four minutes the picture has shifted.”

There are broadly speaking two main branches Astrologers fall into, Horary and natal Astrologers (but if you look at main index you will see lots more, like vocational, electional, mundane etc) will look at questions throughout different forums using techniques like Secondary Progressions, Solar Arcs, Transits, Solar returns, which can take years of studying, research and practise.