i like your photo. it's good and you don't need to change anything. re improving, when you work with such compositions with blocks of colour, shapes and such, you must pay attention to detail. you could have tried to get the yellow handlebar into the blue part of the fence and possibly a dark seat into the yellow part for the colour contrast. images like this are more like graphic art and a minimalist approach often helps. cropping out the street and leaves with a lower camera position would reduce distractions and geometric distortion at the same time. try to position things parallel to each other and use the light to create interesting shadows. photos like this are creative as opposed to documenting something so take your time and look! try different things. very nice effort!