Great answer above.
You will need to know his birth/residence place, then you can look up the parish records for his church. (Without it, finding info will be like looking for a needle in a haystack.) Depending on the locality, there may be city directories or other resources. Go online to the CATALOG at FamilySearch.org and see what records are available for that location in Lithuania. Some are only at the FHL but others may be online and atoo. Many microfilms are not searchable by keyword though and you will have to do a visual scan by the year for what you are searching for. Going in armed with as many details as possible will help you make the best use of your tine there, otherwise it is very possible to waste an.entire day goose chasing info you could have found at home. If you are really stuck, you can get a genealogy membership at the Balzekas Lithuanian Museum of Chicago and they may be able to get you started. There is also a Lithuanian Genealogy group on Facebook that can give you search advice.
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