Parts to concentrate on

I’ve been working out this entire offseason since the end of November. I’ve been working on mostly my legs(Calves, quads), abs(obliques, lower abs), chest(clavicular), arms(forearms, tricep mostly), and my back.

These are the last 4 weeks of my offseason, so I’d like to know which things to really concentrate on. Specifically. :smiley:

15 years old, I experienced elbow tendonitis last summer and my season ended very early.
What body parts do you all think I should really target and break down in order to have an injury free season?