"PA" can be translated to either "still" or "yet".
Di pa ako antok = I am still not sleepy/I am not yet sleepy.
I also want to note that in this second example, adding "rin" to "pa" confirms something previously stated.
Di ka pa ba matutulog? = Are you not going to sleep yet?
Di ka pa rin ba matutulog? = Are you still not going to sleep? (As if it's been spoken about before).
"PA", in this context, is like an adverb of time, describing when an action takes place.
--
"PANG" in "panglalaki" or "pang gabi" is a connector, coming before a noun, to turn it into an adjective.
"Pang+lalaki" (adj. = "for boys") + "banyo" (n.) = Boys bathroom
"Pang+gabi" (adj. = "for night") + "trabaho" (n.) = Night work/Evening job
I can't really think of any situations where PA (adv.) and NA would be combined to turn it into PANG.