I would pronounce pa as “paw”, like papa. Would you say it like the a in “apple”?
A dog limps into a bar. The barman looks at him and say "What can I do you for?" and
the dog replies "I'm a looking for the man that shot my pa"./pɑː/ — if I had to use "normal person's IPA", "pah" would be my attempt. This, to me, is the more common pronunciation. Should rhyme with "bra" … assuming you pronounce that like I do.
/pɔː/ — like "paw" or "awe". This is a region-specific dialect, to me. This appears to be the one you're familiar with.
See https://en.wikipedia.org/wiki/Help:IPA/English for a chart.
https://www.merriam-webster.com/dictionary/pa
Relevant for the US.