There are many different kinds of meetings out there for people in recovery, associated with the 12-step program and otherwise. There are even meetings for different kinds of substance, such as Narcotics Anonymous versus Alcoholics Anonymous. Meetings are essentially support groups for people in recovery, where you can connect with others, working through any challenges of recovery and acknowledging accomplishments.
Meetings are a great way to stay involved with the recovery community and take your sobriety and recovery into your own hands.
Inpatient and outpatient programs often model meetings to some degree in group therapy sessions. In addition to this, it is advised to go to meetings while in treatment, and to find a sponsor. After treatment, though, you should continue attending meetings. Find a chapter that you like and settle in.
Not only can meetings connect with others who you relate with, they are a place to be of service to others. Once you have worked the steps, in a 12-step for example, you can sponsor someone who is completely new to recovery. Helping someone totally new to recovery will remind you of the values and lessons you have learned. It will also build compassion and purpose in your life.