Post-grad dilemma

I’m planning to graduate next summer with a Physics BS, and I’ll be submitting PHD/masters applications in the fall after. While I would like to apply in the coming fall I will be taking a heavy courseload and my gpa isn’t very high as of now (3.2 GPA). I still want to continue to do research or something physics/math-related in the time between graduation and grad school. I’ve looked at post-bacc positions but many of them start in the summer instead of the fall. I don’t know if I should look at a co-op or an internship of some kind, or if I should look at lab tech positions.