A old trick is to put 2 barbells or stout pipes across the safety's of the rack. Stand in between the bars/pipes and dip. Adjust the height of the safety so that the bar/ pipe is at the correct height for you to dip
This is what I do for dips although I have long pieces of timber off-cuts which I place across the safeties.
For lower body, there is RDL, Good Mornings, lunges, etc.
Ditching my gym membership in favour of buying a power rack was the best decision I ever made. I'm free to train whenever I want, listen to whatever I want and swear as much as I like!!
Awesomeness awaits you.