I think there are quite a few great ways to get better at photography. I've taken lots of courses and I find that courses are really useful to expose you to various techniques, styles of photography and different subject matter. There are also camera clubs, online photography challenges and competitions to help you improve taking images.
However, if you are just starting out, an online course will help you figure out if you are even interested in becoming a better photographer.
Many photographers talk about making photographs rather than taking photographs. Some images are great out of the camera, particularly with our modern cameras, but others only come about with careful attention to the processing of images. The image below is an example of a tricky photograph to get straight out of the camera (SOOC) because it is all white. Normally your camera will try to make everything 18% grey so white scenes look grey and black scenes look grey. Processing or knowing what to expect from your camera will help you get better shots SOOC.
Before to dive too deep, the first thing to do is to learn the basics. Fundamentally, the basics are not too complicated while I hope to cover some topics in my blog in the next little while, there are lots of great resources online. I particularly like the Foundations of Photography series through Lynda.com. You pay for an annual subscription and can take as many courses as you like. It is mostly geared to software but there is lots of photography instruction. The instructor I really enjoy is a guy named Ben Long. He is also the author of a great reference book called Digital Photography and is a photography instructor. He is easy to follow and listen to.
Once you understand the basics of photography - Aperture, ISO and shutter speed, you can use a camera to try and get pictures. Even if you are using the camera on your phone, you can still get great pictures
Photography challenges are great once you are comfortable with your camera and with processing your images. Good one a week challenges, like Life in 52 on Facebook, are good because the groups tend to be supporting and force you out of your comfort zone.
Henri Cartier-Bresson said that your first 10,000 images are your worst. The underlying principle is that you need to take a lot of photographs to become good. Happy shooting!