Training for working in the field of psychology
1. Bachelors degree in psychology. - 4 years.
2. Masters in mental health counseling or marriage and family counseling - 2 years + 1 licensing
Doctorate in clinical psychology or counseling psychology or a doctor of psychology - 5 years + 1 year internship + 1-2 years to get licensed
Medical degree - 4 years + 4 years residency + licensing
Through out the process of grad school and licensing, you are getting on the job training. There's no other way to learn how to do therapy.