Searching for long lost relatives. Joseph Wojtus born in Jaroslaw Poland, wife Anna Horbacz

My great grandfather Joseph Wojtus was born in Jaroslaw Poland in 1896. He emigrated to Canada at the age of 17 and ended up becoming a citizen of the United States. He settled in New York. His wife Anna Horbacz also was born in Poland either 1897 or 1898. She emigrated into the US through Ellis Island in NY.

However... I'm having a really hard time finding any information about relatives they may have had or who their parents were, etc. Can anyone point me in the right direction for searching this information up??? or even finding living relatives? It's hard because I do not speak a lick of Polish. Any help or pointers would be much appreciated.

@CatWoj8
You need to start with American documents anyway to know their religion, date and place of birth (not just the country) and possibly parents.
Check their death certificates, marriage certificate or immigration papers.
If they immigrated before Poland regained independence you will probably find Austria, Russia or Prussia as the last residence.