Lionel, here is something to try.
Get a bag of Roastin' Ronnies, he roasts a little lighter than most coffeehouses, but, a higher quality bean than most grocery store beans. Heck, all grocery store beans. This is the best start. Most 'gourmet' coffees are roasted too dark and have a strong bitter component. Most grocery stores use cheap Robusta beans and roast hot and light, which gives a sour taste.
If you use a drip coffee maker, grind to a medium fine grind and try adding a tablespoon of sugar for a whole 10 cup pot. Add a teaspoon for 4 to 5 cups. Make coffee normally and allow to sit for 5 minutes before pouring.
If you use a pan (yes, I use a pan) add one scant teaspoon of sugar and 3 tablespoons of coffee ground fine. Add cold water (2 to 3 cups) and bring to 185F slowly over medium heat. Stir once. A foam will form on top and bubbles on the edges. Allow to sit, heat off for 5 minutes, pour slowly through a fine strainer. This is some good stuff. I know, stupidly complex for a cup of coffee. It will have no bitterness.