Our Betta Fishs

Question
My mother brought my brother,sister, and myself one Betta Fish each.  They were brought from a discount store.  The tanks that were given out to us were small plastic tanks with small slits on the top.

1.Is the tanks good enough for the fish?

2.The people at the store told us we could use bottle water for the fish. How high should the water in his tank be filled?

3. How often should the water in the tank be changed?

4.When I change the water, how do I clean out the tank?

5.Are other items needed for the tank? The tank has nothing in it, except for the fish.

6. The food that was given for the fish is called HBH BETTA Bites.  Is this brand good enough for the fish?  Is there any other types of food that should be given to the fish?

7. Also, the directions on the fish food container says to give 6-8 pellets to the Betta fish twice a day and to remove uneaten pellets.  The container says if the pellets are not removed, they will cloud the water.  Is it necessary to remove any of the uneaten pellets?  If so, how do I remove the pellets without disturbing the fish?

I'm very sorry for asking many questions, this is the first Betta fish I've had.

Answer
Ok i will answer the questions in order.

1.No the tanks are much to small for the fish you need at least 5 gallons of water per betta, but you can't put the bettas together or else they will kill each other!

2.You can use bottled water, but you need to put stress coat in their so the harmful chemicals are removed for your fish.

3.With the 5 gallon tanks i would say once a week, and you need to get a mini siphon hose from your local petstore to take the water out and you will need a bucket. What you do is stick the end of the siphon into the tank and push it in the gravel so all the leftover food and waste is taken out.

5.When you get the bigger tanks you will need a heater, filter, gravel, decor., and a light.

6.the food you have is a fine brand along with the pellets though feed him frozen bloodworms at night then pellets in the morning or the other way around.

7.Yes you must remove the uneaten pellets with a fish net you can buy them at walmart or a petstore.