I just purchased 32 week plan.
However, for the past 4-6 weeks, I’ve already done some weight lifting (squats, hamstring leg curl, and deadlifts) 2-3 times a week.
My question is, should I skip all gym work for 4 weeks (Fall Foundation) and wait till the adaptation phase starts?
I’m asking because I would not like to lose what I’ve done already in the gym and also it sounds a waste of money 
as I pay quite a high monthly fee for the gym).
Thanks for the advice in advance
It kind of depends on when you want to start your season. You don’t want to finish the resistance plan too soon so you don’t reap the benefits but also you don’t want to start it too late and not have enough time to get in the proper base training and interval training before your goal events.
So ideally you will finish the resistance training 24 weeks before your goal event. This gives you time to finish the 32 week plan and an interval plan afterwards.
Since you have already have started with weight training I would jump right into the adaptation phase. Honestly you wouldn’t even need that since the adaptation phase is about getting use to the weights which you have already done. But you can benefit from some of the muscle tension workouts that would accompany the weight training.
So I would recommend skipping the first 3 weeks of the fall foundation and jumping right into the weight training since that is where you are at. But again this comes down to timing.