BGK, just curious but how old are you? Do you think you could also have your parents try and help you with the tank?
If this one does not live, don't beat yourself up - from what I have heard they need very special care.
I suggest taking time like you are now and learning a lot about how to care for them.
Weekly water changes are very important. When you add the water in, to be safe it would do no harm to treat it with a dechlorinator. Also, letting it sit out to adjust to the tank temperature is a very good move - too cold or too hot can shock the fish.
Do not add any chemicals to adjust your pH. Changes in pH are more stressful to fish than a steady pH. If you bought your fish locally, then he is used to your local pH.
Do not try and force feeding and be careful about over feeding. Eating too much is as bad as not eating enough!
Go to your tank and look at the filter. It should have a brand name/model on it. Post that here.