There are two things that muck up French press coffee: water that’s too hot and badly ground coffee. Boiling-hot water scorches the grounds, making them bitter, while too much fine grit in the grounds makes the pressed coffee muddy with sediment and difficult to press.
Both elements are simple enough to fix. All you need to do is give your water a minute to cool before brewing, and invest in a burr grinder, which breaks beans into more evenly sizes bits. Or you could ask your coffee vendor to grind it coarse for you.