Well bboorreedd11, I am not an old pro but I am old if that counts. The first thing that you need to consider is whether or not you have actually cycled your tank to establish a mature filter. My guess from the nature of the question is that you have not. Having come to that conclusion in my own backward thinking way, my first suggestion for you is to get a good liquid type test kit such as the "master freshwater test kit" made by API. It will allow you to check your water chemistry for ammonia, nitrites, nitrates and pH. If ammonia or nitrites get above 0.25 ppm you need to do an immediate partial water change, even if you just did one yesterday. Levels above that will harm your fish and even at that level they can cause long term damage to the fish. Once the nitrogen cycle is firmly established in your tank, an indicator of when to change your water is when nitrates are at least 10 ppm above your tap water reading and preferably before nitrates in your tank exceed 40 ppm. After a few water changes for nitrates, you will know how often you need to change water based on how often the tests are telling you to change it.
The pH test that comes in the kit is often nothing but a curiosity test. Unless you are setting out to keep some of the more difficult fish or you happen to have very soft water, the pH you have will be what comes out of the tap or slightly less. Most water good enough for people to drink is good enough to keep the common fish in. There are those that need a particular pH but most are very flexible if the pH is anywhere near neutral. If your tap water is very soft, it may be necessary to add buffering to it to help stabilize pH. Before you do that, come back to the forum with details about what your tap water and aquarium water parameters are so that we can be of more help.