What should be an aim of a life?

It depends on the person's character. There are many people whose one aim in life is to earn a lot of money. Others seek personal aggrandisement (politicians and rulers). Other people such as singers aim to achieve fame and fortune. There are also philanthropists ( rich people who help the poor and those in need, especially by giving money) and those whose life is very religious as they devote themselves to religion (or to the spiritual side of life). There are also those who have a thirst for knowledge, that's why they dedicate their life to learning. Others aim to live a decent quiet life in the bosom of their family and have a decent and secure job. There are also those whose family comes first (=the most important thing in life) and they devote themselves to their family because it means everything to them. Others aim to pursuing their goals and dreams. However, there are those who live an aimless life and a meaningless existence.