How to use the four wheel ?

Hello, as already written in another thread I bought a Suzuki Vitara 2.0 Bj 98. This is now still made fit in the workshop and can then be picked up next Friday. Freu! But now my question. One of my motivations for buying the Vitaras was my masive fear of driving in snow and ice. I have 2 children who have to be driven daily to school. So I can’t stop. Now different people have advised me to go to a four-wheeler. Only w he is best used in winter?? In another thread in this forum, I read that the Vitara would be a tailshoe in winter without four wheel. Helpeeee! That would be my nightmare!! It would be great if someone took the time and explained to me the correct use of the four wheel. Many thanks Martina P.S. How do I test when picking up whether the all-wheel drive also works?