This is perfectly normal question if you're considering moving here. Whilst you're considering moving to Fiji, you'll be told numerous horror stories of home invasions, military shootings, stabbings, rapes, goat sex and murders! You'll also be told that you'll need to live in a gated community...
Fiji is probably less crime than your home town. Just follow the simple rules of the world and you'll be fine.
If you're going to be a prick and flash your money around, you deserve to be robbed. Have some respect for the people here. The majority of Fijians earn very little money and the last thing they need is fat white men flashing $100 notes around.
When you go to bed at night, lock the door like you would in your own country.
If you're in the pubs and clubs, follow the same rules as if you're back in your own country. If for any reason you end up being pestered by someone, tell them to bugger off. If they don't get the message, make a lot of noise and they'll soon leave you alone. Fijians hate being humiliated and rather than retaliate, it is likely they'll walk away very quickly.
Fijian people are deeply respectful and if they have food they'll nearly offer you some they know you. They have a great sense of humour, love sport and are very proud of their country. Oh, don't be a fool and ask about the political state of the country. Keep your opinions to yourself, you're a guest here and they have welcomed you here.
During the sugar cane harvest (which off the top of my head runs from around the end of July to November), you'll see people walking along the streets with Sugar Cane Cutters (Machete’s if you want to go Hollywood on the matter). Don't worry, these are just workers heading to and from the cane fields, they're not going to chop your balls off for your iPhone.
There are no poisonous spiders here in Fiji, so ladies you don't need to lift the seat every time you need to powder your nose!
Are there sharks in the ocean? Are you a moron? As long as you're not swimming around with a leg of lamb hanging from your swimming costume, you'll be fine.