Which is better : to enjoy your money when you earn it or to save it for the future?

I think saving money for the future is better than spending money soon after you earn it. The reason is that we need money for solving problem and taking care of our families. [Your sentence was correct, however, it's always nice to have parallel structure - you had a verb-noun (solving problems) so it's nice if you have another one (taking care of our families)]

Things sometimes happen suddenly in the life, such as death and other disasters. Death and disaster are good examples that happening things. When you are in such events, you often need some money. If a member of your family dies, you need to prepare a funeral, and if your house is hit by a storm and broken damaged [toys are broken, houses are damanged], you need to repair the house it. For these things, you should have to pay much a lot of money. If you don't have extra money, you have another trouble as well as shock and sorrow though shock and sorrow already make you tired. That is bad when you are sad and tired [this sentence is redundant]. Therefore, saving money is important because money can help you if you got to trouble.

When you make a family and have children, that means that expenses increases. It is natural to grow up increase expenses when the member of family number of family members increases. And, if you have children, you need much (a lot of) money for better education and club activities and so on. The cost is too much so some people should have saved money for the future with children even before they have babies. You should spend money not only for education but also the house when you have children. Only you and your partner can live in a small flat, but you should move bigger house when you have children because chilren need their own rooms.you should prepare rooms for children. So, growing up children means high expense. Therefore, you need to save money if you want to have family in the future.

In short, it is better to save money than spending to spend it because you need money when things like disasters and death happen and you have a family.

[Overall, nice work. The usage of "you" is a little informal, and college students would never use it, but based on your proficiency level, good job.]