Where to focus?

I'm a 20 year old art student who is planning on improving my gesture. Would you might telling where to work on and hopefully I can improve it by the end of summer

If you don't already have a specific focus, I would start with 30 minute classes every day, following this guide:

Gesture basics #1: Line of action
Gesture basics #2: Head, ribcage and pelvis
Gesture basics #3: Joints

And also keep this practice philosophy in mind as you go: https://line-of-action.com/happens-30-seconds-isnt-enough/

Keep us posted on your progress! :)

I didn't know I had to use some sort of program but I'll check.

What program are you talking about? You are free to draw with pencil and paper.