What do you have to do to take care of a fish?

First thing you need, a good book on fish keeping

Then find a 10gal tank "kit". This should have all the basic gear you need. Maybe not the best stuff, but good enough to get a tank system running.

10 gal tank means small fish. That's OK, there are any number of smaller species that that can keep in a 10- gal tank as long as you set it up correctly.

Easiest?

A betta fish. 10 gal is bigger than you need, but then the tank is only lightly stocked, and so easy to care for. You can also add other fish with a betta once you get the tank running smoothly. Bottom dwellers like smaller types of cory catfish are good.

Another good 10 gal setup is White Cloud Minnows. These are small and hardy little fish, and quite active and pretty. They might breed, but they wont overpopulate the tank. Advantage with them is no heater needed. They are cold water fish and happy at any sensible room temperature.

Food? Normal fish food is pellets or flakes of processed food. If you don't know it's hard to tell what it is. But product labels will say things like fish or shrimp meal (just bits of fish or shrimp ground up and dried) You can also buy brine shrimp or bloodworms, either dried or frozen. These are small critters that are like the natural food of small fish. But it's best to feed those as a treat.

BTW, good on you for doing some research first. Too many questions are about "I've got 5 goldfish and a bowl, what should I do?" At least you won't make that mistake.

Ian

Get a great 10 gallon kit it should have a filter a light hood in the tank sometimes they come with heaters with no heater $35 with heater 45+ go to walmart there probably cheaper there.The kits come with food and water conditioner, but i wouldn't really use those buy omega one foods it's what i use one of the best fish brands out there i say 1st or 2nd best. When i was new at fish keeping i started with one betta in learned a lot about fish keeping. The fish hobby is really not that hard all you need to do is cycle your fish tank i did it with a betta in his 4 years now there really hardy. After you cycle your tank which tanks 4-6 weeks sometimes less you can add fish just buy a water test kit to test your water, water conditioner get prime #1 right now get silk plants and caves. Make sure your filter runs well in always leave both the heater and filter on. You should spend around $45-$55. Try ebay or other online website you might find it way cheaper then in pet stores.

I would totally do a betta fish with some shrimps. :) I have kept tons of fish tanks ranging from wee little 5 gallons to 60+ gallons. My favorite is a little 10 gallon that contains a betta I imported from Thailand, and 4 ghost shrimp. Its extremely heavily planted with a little clearing in the middle. My husband and I make a game out of trying to find the ghost shrimp. (No matter how hard you look you CAN'T find the last one, only to find out when someone else points it out to you, its on a leaf an inch from your face.)

It's also funny when you drop a favorite food item in. Shrimp frantically running for its life clutching a bloodworm with betta in hot pursuit. You just can't beat the combination in terms of hilarity and quality tank watching time.

In my ten gallon tank I started out with a guppie then added 5 neon tetras ... I bought the kit for about 35$ at Walmart it came with sample fish food and a sample of aqua safe stuff to add to the water and a filter. First you set it up and have it cycle for a week or so before adding fish. I bought a thermometer at Walmart for 2$ for my tank.

Fish food flakes

A fish filter

Fish tank with a light on the lid

WATER lol

If goldfish are in the dark they loss there pigment

Do not put snails in the tank to clean it

The snails will love the fish will die