Moving away from pixel art games

So I’ve made about 20 different games in the past year which all use simple pixel art. It’s time to move on. My next project is a type of top down shooter where the player will have a full 360 range of motion (not appropriate to use pixel art for this one). I’m not sure how to start… I have heard of vector art, but I’m not sure how easy that is with Java (I am not interested in learning how to use a graphics library like LWJGL, but I would be willing to learn if that is the only option that makes sense). I would appreciate it if someone could point me in the next direction, or to a tutorial on more advanced graphics with Java.