The general standard is 1 level tablespoon for each 6 ounces of water. Less than that will make bitter coffee. If the coffee comes out too weak for you, gradually add more.
Extracting flavor from coffee requires the right water temperature - 195 - 205. Less than 195 means incomplete extraction. Above 205 burns the coffee & burned coffee is bitter. The really cheap coffeemakers don't have a boiler that's capable of the right temperature. If you don't have a thermometer, let the water boil, then wait 20 seconds without heat. The water should be either filtered or bottled. Water is the main ingredient in coffee. A pour over is the best inexpensive way to make 1-3 cups of great coffee if you don't want to spend a lot on a coffeemaker.
If you use already-ground coffee, depending on how it is packaged, it may be stale. Once coffee is ground, the oils in the beans start to become rancid. That's why picky people like me have a grinder & grind each cup just before use. And, the fineness or coarseness of the grind also affects flavor and the strength. The ideal grind depends on your brewing method - pour overs required a different grind than coffeemakers.
When I have company over & they're not very picky about coffee, I get a big kick out of seeing their reaction when I make them coffee.