The GPP phase is a great time for you to work on the foundational movements of the human body- squat, hinge, lunge, push, pull, carry, and rotate. Once you’ve become proficient in each bucket, you can then progress to more specific and advanced training.
If you are struggling with any movement or learning it for the first time, it is extremely helpful to train the base positions- I’ve given you two examples here using the squat and push-up:
To train the bottom squat position (which is usually the most challenging for people), I am performing isometric holds in both the beast plank and deep squat positions- these positions are pretty much identical and is called triple flexion- the only difference is that I’m upright in the deep squat and facing down in the beast plank. Transitioning between the two is also important for building further awareness of maintaining triple flexion. Perform up to 5 reps of these at a time and once you feel like you’ve owned the bottom of the squat, you can incorporate the full movement.
I pretty much used the same approach for the push-ups; the only difference is that I’m performing isometric holds in 3 different positions- the top, middle, and bottom. Similar to the squat, the bottom is the most challenging so you can just do holds there if you know that you are already strong in the other positions. See if you can work up to a minute before trying actual push-ups again, and you should see a big difference in your strength.