No reason you can't initially fill the tank usinfg a garden hose as long as it's reasonably clean, I'd purge it first. I assume it's connected to the mains and not a rain water tank. Youll need to treat the water with tap safe. When you do top ups though don't use the hose as you'll need to...
Ok tropical/ so look on line for advice - Fluval's web site will almost certainly give you start up instructions - you'll need to replace the filters and buy some tap safe.
Paraquatics stock Fluval so may be worth just taking the tank in (before you fill it with water!)
Also check everything is...
Loads of advice available on line of course but first question might be what are you keeping in it? Cold water/tropical/salt water?
Most important thing is take it slowly and let the environment stabilise over a couple of weeks at least to ensure water quality is good before adding fish.
Worth...