The most important thing to improving your food life is eating the best quality foods. Start with having the best basics in your kitchen.
Salt: Stick to sea or kosher salt. Find something else to use that can of iodized salt for, like a cleaning abrasive.
Pepper: Invest in a quality grater, with an adjustable particle size, and a good supply of multicolor peppercorns. Upgrading to the multicolor peppercorns is huge compared to the black peppercorns, and the scary black 'powder' probably shouldn't be called pepper.
Good olive oil: I'm spoiled by the nearly empty bottle we bought in Italy, but find a quality flavorful oil and store it in a dark cabinet/bottle at a good temperature.
Other cooking fats: I really like safflower (yes, safflower not sunflower) oil for a neutral, high-temperature cooking medium. Use a touch of butter (regular, full-fat, unsalted butter) if you're looking for that taste. Consider mixing the safflower with a pat of butter to get the high-temperature benefits of the oil with the taste of butter. For large quantities of frying, try a standard canola or vegetable oil blend (cheap!) or a peanut oil for a strong taste. People do, but personally I prefer not to cook with olive oil other than tossing at the end of cooking. It destroys some of the flavor, and olive oil is expensive to use in large quantities. I also like to use a touch of sesame or peanut oil in a dish to add a lot of flavor. Try mixing it with another oil because they are usually quite pungent.