Success is setting a goal and then achieving it.
The first part is very important: if you don't know what your goal is, it is extremely hard to achieve it. (Unfortunately, in this world there is much confusion and sleepwalking regarding goal-setting and success.)
We all want to be successful in life, but what kind of success are we aiming for? Financial success, success of social recognition, success in relationships, success in love, success in expertise, success of spiritual fulfillment? Is it one of those - or all of those? Is it something else? What is success to you?
Most people don't have a clear vision of success, because they don't know exactly what their wants and desires are. In these situations many times people confuse or substitute one goal for another. For example, they desire emotional success, and believing that money will magically make them happy, they aim for financial success - they end up achieving the wrong goal.
The desires and successes of others also influence ourselves, sometimes in positive and sometimes in negative ways. Make sure that you set your own goal for yourself.
If you define your goal as clearly as possible, you're are already halfway to becoming successful.