You do not need to have a mentor before you can become successful in life. There are many successful people in life that does jot have a mentor.
Some people only like after a role model and they may want to be like such people and work towards it.
But know that success is not about having a mentor or looking after someone as a role model. It is about how smart you are in achieving successes. Opportunity and exposure are also very important.
I think mentor or mentorship is only a modern thing. We even have internet now and plenty of info can be found here for free, so this eliminates more the need of a mentor. I think most mentors are not really successful on the field that they are teaching but they are only good at sales talk. They need to, because this is like their source of income/living. If there are more legit mentors, those must be free and the person is truly successful.
We might learn better here but there might still be no guarantee to be successful too. When you say role model, I think this is like an inspiration. We can have this as well for free but I think another purpose of mentor is there will be someone that will tap you in the back (encourage you).