They can ask friends, family, clergy, counselors or doctors. The most well known self help program for people having difficulties with drugs and alcohol is Alcoholics Anonymous or Narcotics Anonymous. A person can receive professional help, called treatment, at a hospital, a treatment center, a mental health office, a counseling center or a counselor, psychologist or doctor's office. The person who helps with treatment is called a counselor, a psychologist or a doctor. The helper's title depends upon the training and the licenses they have.
Some counselors have a bachelors degree from a college.
Some have a masters degree. A doctor has a medical degree. The main difference between the doctor and the psychologist is that the Doctor, MD, with the medical degree can help with physical problems. The medical doctor can prescribe drugs and do operations. All three, the counselor, the psychologist and the medical doctor, can do further studies to learn about the difficulties around alcohol and drug use and get a license or establish a specialty.