After explaining the exposure triangle one of the first things I teach new photographers is the importance of depth of field. I have them download a depth of field app on their phone to help them. Why? Because new photographers almost always buy the 50mm 1.8 because they want pictures with a blurry and dreamy background (their words, not mine). Too many new photographers do not realize you just can’t set your f-stop to 1.8 and expect magic.
In short- learn depth of field. Put distance between your subject and the background, don’t be afraid to stop down and most importantly, look what’s behind your subject before taking the picture.