Fish are generally quite easy to fit around holiday absence. However it pays to do some preparation first though, and having someone who can pop in once or twice a week can be very useful. Without a doubt, over-feeding is the biggest threat to an aquarium or pond left in the hands of a novice.
If you have a human caretaker available, show them the normal state of the filters and life-support equipment ahead of time and leave the phone number of your favourite fish shop near the tank. Hide the main containers of food and leave labelled portions to make feeding issues less likely. Consider using tablet foods to simplify the quantities offered, or in the case of frozen foods, use an ice cube tray with portions frozen into blocks of water.
Leaving an aquarium unsupervised is also an option and automated feeders can be used to keep home-alone fishes fed. Install such units a few days before departure so that settings can be adjusted and the correct quantities used. If in doubt, under-feeding is far more healthy than over-feeding and intervals such as weekends can be left without any food provision. Old-fashioned plaster-based dissolving food blocks are still available, as are their modern equivalents which tend to have less impact on water parameters such as KH.
Ensure that you carry out routine maintenance such as cleaning filters or performing water changes before you go to avoid any complications or failures due to blocking etc.