Take the course. You can only get the most out of any tool if you know how to use it. That is especially true of a tool as complex as a camera used to do a task that is considered an art.

You wouldn't upgrade from a family sedan with an automatic transmission to a high end exotic sports car with a non-synchronized manual transmission without getting someone to teach you how to shift it would you? (can you say "double clutch?") But even if you can work your way through the gearbox (or properly set exposure with a particular camera), that is only the beginning of learning how to see the quickest line through a series of curves or how to out brake your opponent at the end of a long straightaway (or how to properly compose a photograph so that it communicates what you wish to communicate).

Learning how to operate a particular camera is easy. Learning how to see things photographically isn't easy, but that is what will improve your photography and is what a well taught introductory photography course should help you learn to do.

Even if you choose to never upgrade your camera learning the basics of photography will improve the results you get with the camera you already have. For more about when you need to upgrade your camera, please see: When should I upgrade my camera body?

There's a saying that has been around photography for a long, long time: Gear doesn't matter.

This is true, but it is only a part a larger truth.

The fuller truth is: Gear doesn't matter... until it does.

So what does that mean? It means that until the gear in some way limits the photographer from doing something that the photographer already envisions and has the technical knowledge, skills, and ability to pull off then the gear is not the limiting factor - the photographer is.

In the end it depends on your current skill level and the quality of the course. But based on your own admission in the question, you have "poor experience." Until you can explain what about your current camera is limiting you from taking specific photos that you can envision and that you want to take, the area that needs improvement the most is your skill level and experience, not your camera.