Water is the most important element for growing orchids and the one that causes the most concern for a beginning hobbyist. Too much water encourages rot and too little is certain death. Fortunately, Orchids are very hardy and will except a wide range in the amount of water.
Certain Orchids like Phalaenopsis and Lady slippers like to be moist all the time. Cattleya like to dry out in-between watering.
The amount of water will depend on the Potting Medium you chose. Some like sphagnum hold a lot of water and dry slowly. Chose these types is you want to be able to ignore your plants periodically. Others dry fast like Bark, chose bark if you like to water more often and thereby control the water.
Growing outdoors in summer heat will evaporate the water faster.
Humidity and strong air circulation will require changes in watering.
Outdoors in Florida under shade-cloth we water every day. Indoors we recommend every 10-14 days as a good starting point. There are so variables indoors that every recommendation is only a starting point. You need to watch your plants and see how they respond to your methods.