Choosing the correct fly fishing equipment is not difficult once you know what type of fishing you will be doing. Are you trying to catch salmon off the ocean coast or smaller 12-inch trout from a mountain stream in Montana? Each condition will generally require a different size rod, reel, and line to maximize your ability (and enjoyment) in catching fish.
Rods, lines, and reels are all matched by "weight" to more accurately and easily present your fly and give you the necessary casting distance. It all starts with the line weight for your particular type of fishing. Rods are designed to cast or a specific line weight while reels are designed to hold specific weight lines. Smaller weight combinations (2 to 4 weight) are generally used to catch small fish. Medium size combos (5 or 6 weight) are good for fishing rivers and lakes where you may catch fish up to 4 or 5 pounds. Larger weights are good for those big lunkers.
You will also want to consider items like waders and wading boots. These will undoubtedly make your experience better but more importantly, safer. Vests are used to carry all your gear. And there are miscellaneous accessories like nets, sunglasses, and other tools that will also help make your life easier when out on the water fly fishing. I won’t kid you, it will take some money to purchase the equipment, but you shouldn’t have to take out a second mortgage to get a good quality rod, reel and line. Just make sure you purchase the correct weight for your type or fishing and you’ll be set.