what should i definitely do in life?
Because life itself does not come with a set of instructions outside of human biological instincts, there is no one definite thing anyone should do in life. All individuals must decide for themselves what is a valuable use of their time, and so any attempt at compiling a list of what everyone should definitely do will be too general and run the risk of being unsuitable for any given person.
OK, at least tell me is it worth falling in love?