The students are the ones who know if there is a positive learning environment more so than the faculty. Once you have chosen a school and have begun a program, you need to become thoroughly familiar with the policies and procedures involved in completing the degree you are after. It is your responsibility to take care of yourself. This should certainly involve utilizing the faculty advising and other features of the program you are in, but you bear the final responsibility. You should also work closely with you instructors whenever you have questions about or problems with a particular class.
Many students find it beneficial to study in a group.
You can integrate yourself into whatever study groups are available. Encouraging the use of study groups is one way that successful programs can reduce student attrition. Plan on working hard Graduate school can be a very absorbing and rewarding experience. But it takes a total commitment. Don't go to graduate school with an attitude that you just want to get by.