Hello Pam,
You should try the online website www.irishgenealogy.ie for church records for Co. Kerry. This is a free site set up by the Irish government. Look also at www.askaboutireland.ie (another free site) and search for your family on the Griffith valuation.
I would advise you to keep an open mind on th date of birth.
Most people who emigrated were illiterate and undocumented. They didn't know how to spell their names and hadn't a clue as to what age they were. At the port of arrival their names were recorded phonetically, their ages were only guessed, and this is the information that followed them for the rest of their lives.
The proof of this occured in 1909 when the old age pension was introduced into ireland. People had to prove their ages and were forced to go through baptismal records to establish when they were born. That is why there is such HUGE discrepancies between ages in the 1901 census and the 1911 census of Ireland. Dates were found to be out by as much as twenty years in some cases.
If you don't know John's parents names, try looking at the names given to subsequent generations. children were almost always called after grandparents.
Hope this helps you,
Anne Dennehy