The activecampaign integration inside memba does few things
1. When a new membership is created inside memba then memba checks if the same user exists inside active campaign, if it does not exist, a new contact will be created inside activecampaign
2. When memba creates a new user it adds two custom fields inside activecampaign, one the user field and the other password field, the format for the user custom field will be something like yourdomain.com_user and the password custom field will take the format yourdomain.com_pass
3. The user custom field above will be populated with the username created by memba inside WordPress and the password custom field above will be populated with the actual WordPress password created by memba when creating the new user.
4. Memba will add a tag to the contact with the format yourdomain.com_memba_tagging_new_user which can be used for automation or other actions inside activecampaign.
5. Creates a tag with format yourdomain.com_memba_created_membership_product_title
Except for the first four actions which is created only if memba creates a new user, i.e, when a new user is being created inside WordPress, the fifth action which creates a tag about the new membership creation will always happen.