Keep the beer in the refrigerator, preferably at the recommended temperature indicated on the product.
Beer needs to be taken care of even after it leaves the factory. The best way to preserve its quality is to find a place for it in your refrigerator immediately after purchase. It's worth putting it in even if you don't plan on drinking it for weeks or months. You wouldn't leave milk out at room temperature, would you?! Think of your beer the same way. If you want to preserve its flavor and avoid oxidation, store it at the temperature indicated on the product until it's time to sip it.