Inpatient rehab (and outpatient for that matter) is what you make of it. There will be people there who are only in treatment because they were forced, or guilted into going. I still remember there was one guy who flat-out told me that he was going to drink/use as soon as he got out.
There will also be people who are there on their own accord, really want to get sober and who are willing to do anything to do it. Stick with this latter group.
The biggest key is to not fight the process. Open-mindedness, willingness and honesty will get you far. Just like with most aspects of recovery, some things they may suggest that you do will be uncomfortable. But that uncomfortableness breeds growth.
And as others have mentioned, inpatient is just the first step. The rehab will make a lot of suggestions of things you should do when you get out. Do them and the growth will continue.
I am grateful for my experience in inpatient rehab. It was a once in a lifetime opportunity to turn my life around. I didn't and still don't take that opportunity for granted.