Hi Laura,
As someone who has recently moved to Malta myself, my advice would be:
- Buy an umbrella/wellies for the infrequent but heavy rain
- Learn a route to work that you can walk, rather than taking a bus, sometimes they get caught in traffic and walking is quicker - it is for me anyway
- When you buy bottled water, do it in bulk!
- The 'Dubliner' in St Julian's serves an awesome Guinness if you are into that sort of thing
- If you don't have a car, rent one for the weekend and drive about to see what's what. Although it's a small island, there is lots to see
- Do a scuba diving course - it's the best place in the Med for it
- Sunscreen

That's all i can think of for now.
If you need any help with anything, just give me a shout.
Tom