We have several online tutorials that are often helpful for assisting new users make use of the IPUMS data extract system.
Regarding specific variables that will help answer your question. BPL is the “birthplace” variable that identifies where each respondent was born. There are many variables pertaining to ‘work’. I’d suggest first looking at the IND or OCC variables for “industry” and “occupation” codes, respectively. We also have integrated industry and occupation variables, see IND1990 and OCC2010.
I hope this helps. Please let us know if you haven any additional questions by emailing firstname.lastname@example.org