The IFHF is a quasi-governmental non-profit organization. It seeks to make Irish geneological data available online. It takes the place of 32 (or more) county organizations. Everything is in one place instead of 32 fiefdoms.
Google the Foundation's name. Dbl click on the 1st listing. Dbl click on "online research service." That should get you on the trail to the database. It is relatively easy to use.
The names are no relation. I am a shade-tree geneologist. When doing family research, I noticed there were a lot of posts which went unanswered. I am retired. Thought I would enlighten the world on the existence of this new database.
1820 sounds a little late. Men generally married in their mid to late 20s, women abt age 20 +/- 2 yrs. In your searches, remember that the farther you go back from 1840, the lower the chance that a rcd survived. 1820 is pushing the limit.