You should hamster needs constant access to water and this is best provided by using a bottle. You may also want to give your hamster a dish to serve its food on.
A bottle is a better choice than a dish for your hamster’s water as it will keep the water clean and prevent it from spilling into the bedding. Water trapped in bedding can potentially cause fungus to grow which can lead to infection. Water bottles specifically designed for hamsters can be bought, and you should place the bottle at least three inches from the floor, or a bit lower for dwarf and Chinese hamsters, where your hamster can reach it standing up but not easily climb on top of it.
A food dish is not strictly necessary as most hamsters will be happy to eat from the floor of their cage and will often take food given on a dish to store elsewhere. Your hamster may also enjoy foraging for food in bedding. However, a dish can still be useful as it allows you to more easily measure servings of food and gives you a general idea of how much your hamster is eating.
If you do give your hamster a food dish then it is advisable to use a ceramic or metal dish rather than a plastic one so it cannot be chewed.