Society and the rol class

In this class I have learned about the humanity and what they are supposed to do in the world, like help the people; also we have to try to change the world in a different place, we have to make it a positive place; doing positive actions.

Is amazing how the world could work better if we want to improve it, we can do good things like helping the others in our free time, sacrificing our weekends to serve the neediest. We can make a difference, because for a community that is not much, but have an important meaning to the one you help.

I would like to know how to help the others, because you can go and try to assist them but you don´t really know what they need or how to treat them, so my question would be:
¿How we know that someone want our help? , because is easy to see and say they need my help, but maybe they don´t want it, so ¿how we now to who we have to offer our help? and ¿how we help them: in an economic way, spiritual or what we offer to them?