fiji- sailing cruise or just island hop?

Hi guys I'm a 22 year old female travelling on my own to fiji for a week on the way to australia and I'm wondering how best to budget my time and where are the must stay places. I'll be on my own so I want to meet people fast and easily. I do enjoy the nightlife but I also want to see the landscape and experiencing the culture. Are those 3 day sailing cruises good for seeing the islands or should I just island hop myself? where is the best place to go with lots of ways to meet other backpackers? A whitesand beach is a must. Any opinions or ideas?
thanks

There is an adventure cruise called the Tui Tai whcih runs short trips (3 to 5 nights) which include all sorts of activities like diving, snorkelling, hiking, canoeing, island visits etc. It comes highly recommended.

A few days trip like this and you can do all the cultural and sigtseeing stuff you need, then you can save your leftover cash by finding a nice beach and just chilling out for the rest of your stay.