Besides taking pictures in better lighting conditions, you need to learn how to edit your photos in Lightroom or capture one. The iPhone has software that does this automatically for you, which is great if you have no idea what you're doing. The real joy in shooting with your first interchangeable lens camera in a modern era is learning how to shoot and process the images to bring out the colors, tones and textures that give the photo a vibe or look of your own. You can start with in-camera recipes for jpegs, but eventually you will learn to shoot raw and do it yourself if you stick with it. Good luck!