The fastest and easiest way to improve your camera's image quality is to put a better lens in front of it.
With so many models to choose from, selecting the right Canon lens is not always easy. The many dozens of lenses in the current Canon lens lineup each fill a specific niche. Unless you spend a significant amount of time reading the reviews, you need some quick direction in finding the right lens or lenses for your particular needs.
Having used all of Canon's current lenses along with a significant number of third-party offerings from manufacturers including Sigma, Tamron, Samyang, Tokina, and Zeiss, I am uniquely qualified to guide your lens selection.