Without a doubt, the single highest point of leverage in your violin journey is learning how (not what) to practice. If you improve this core skill, every aspect of your playing will win.
This, of course, is true for any level of musician. In fact, a novice violinist’s skills will actually grow more rapidly than those of a professional.
Yes, learning song and pieces is fun, but the rewards of violin practice as will as violin performance become far greater when you connect to that music from a place of greater practice mastery.