I am 18 years old and looking to become a wildlife photographer, but am unsure where to start. I am confused due to the many courses, colleges, etc. available. Should I take a course? What will I need?
If you're going to take courses, I'd suggest you take them in zoology, wildlife preservation and management, or related fields about wildlife. While learning to master your camera and getting the correct lenses and support gear and learning the proper techniques for the type of wildlife you want to shoot is going to be important, the one skill you absolutely must master to shoot wildlife well is fieldcraft.
If you can't get to where you can see the beasties, you're not gonna be able to take pictures of the beasties.
Wildlife photography isn't just about snapping shots, it's also about learning how to stay downwind, how to use a hide or ghillie suit, how not to stress out an animal, knowing the right locations and seasons to find them, what they feed off, and what their natural behaviors are. At its best, it's about knowing about the animals as individuals and families. About knowing their biology, their anatomy, their breeding habits, the destruction/preservation of their habitats, migratory patterns, etc. etc. etc.
The quality of an image typically is about the time, effort, talent, and sheer determination the photographer put into getting the image. Go watch a behind-the-scenes episode of any of the more recent HD BBC wildlife series, such as Planet Earth and realize that each of those short segments probably took anywhere from six months to a year to plan and execute. That living in a hide for three weeks in an Amazonian jungle is how that National Geographic photo gets taken. That if you want to shoot snow leopards in the wild, you have to learn how to climb the Himalayas.
You can practice with a cheap 70-300 on the backyard birdies. This is the fun of learning and beginning. But I think this type of subject is more a matter of getting out there and doing it than sitting in a classroom learning about how to use back-button autofocus and supertelephoto holds. You can get that stuff off the interwebz. What you kinda can't get that way is terrific knowledge of who's in your own neighborhood.
You don't become a surgeon without first becoming a doctor. Similarly wildlife photography is a specialization of our hobby that you get into later.
I would recommend that you first buy a cheap beginner camera and lens and learn basic photography, click pictures of birds, pets and what not. If you find that photography is to your liking then invest in a telephoto lens, which will start you on the journey of photographing wildlife.
Lastly, it is easy to be enamored by beautiful photographs, but clicking those photographs is often highly technical and requires years of improvement- which, on the other hand may not be appealing to many, so, take baby-steps!
Start by taking photos. I wouldn't worry with a class as much as with finding people to give you criticism and guidance.
Instead consider a Photo Trip. National Geographic for example offers a number of them throughout the year: National Geographic Expeditions. But you can find all sorts if you search Google for things like Wildlife Photography Trips
You can see these generally require:
All participants must bring a digital SLR or mirrorless camera, a laptop computer, and software for organizing and presenting images.
As far as equipment especially starting out, a DSLR would be better than a Mirrorless, but you don't need the top of the line in fact I'd encourage a used body, any DSLR will work fine whether Nikon, Pentax or Canon. You might soon want to invest in a Tripod that also becomes a Monopod --- weather gear can also be important. And I cannot stress enough for nearly any photographer moisturizer with SPF and a hat that doesn't get in your way much.
Then really just start. Whether its a local nature preserve or zoo - start taking photos. The difficult part of wildlife photography is that humans generally push out wildlife so be prepared to travel and hike and get out of cities and suburbs. That's why for this focus a Photo Trip could be a great way to jump start yourself. If there's a nice zoo near you that could be another place to make friends with.