ditto @Grisson! I bought a little coffee grinder for about $10, grinds enough for about two days. Once you have tasted coffee from your own grinder, you will not go back.
Also, if you coffee maker has one of those hot plates under the pot to keep the coffee hot, TURN IT OFF as soon as the coffee is brewed. The taste of your brew will go down sharply for every minute that you let it cook on that hot plate. Get a little insulated carafe, pour those 4 cups in it just as soon as they are brewed.
With all the selection of beans, grinding methods, brewing methods, etc., coffee can be an art that you can take just as far as you want – or not.