We start thinking about all the years of schooling we need, how much money this will cost, and how old we'll be when we're finally ready to do what we always dreamed of doing. There are three categories of skills to consider. Each has a different purpose and each is acquired in a different way. Teachers, for example, need teaching skills, writers need writing skills, motivational speakers need public speaking skills. If you do take formal classes, make sure they provide opportunities for practice.
Volunteer work is also often helpful in providing needed experience.
These are the skills that make you a credible candidate for a particular job. They include legally required degrees or licenses. They also include skills or experience or other evidence that make you appear uniquely qualified for your field. If you find it necessary to obtain a degree and attending school full-time, during the day is not a viable option due to either financial constraints or childcare responsibilities, this does not mean you are out of luck and had better choose something else. Instead, look for alternative university and college programs.