A lot of coaches play to win, but there are a lot of coaches out there that just want their team to have fun. Most kids don't like to lose, but it happens to you at some point or another and you only learn from it. Losing isn't always bad for a team, it makes them better and it helps teams to grow.
Volleyball coaching philosophies can be a couple different things, depending on what kind of team you have. If you're on a high school or club team, you play to win, you'll work extra hard to get first. These are the teams who usually get punished for not winning because their coach wants to win so badly. I mean winning is always nice, but you need to have fun doing it as well.
Then you have the coach who just wants their team to have fun while they're out on the court. This is a good philosophy to have, but kids sometimes get tired of losing over and over again. Teams like this are usually recreation teams since it's voluntary to coach.
When picking a team, you need make sure you go over volleyball rules and drills with the team to make them better. You may think everyone knows the rules, but they may have been taught differently then your organization plays, so it's always a good refresher to go over them.
Also, since many kids don't know this, you may want to talk to your team bout the origin of volleyball if you have the extra time. Then there should be drills you should do at the beginning of practice and before a game to get their adrenalin going. For example, peppering (bump, set, spike), stretches, running, etc.
Well whatever volleyball coaching philosophy you have, I wish you and your team the best of luck!