I don't know where you live, but check around see if there is a local genealogical society near you. Often they will offer classes for beginners. Or, you may have a Family History Center near you, they can be helpful, too.
You want to fill out a family group sheet on each couple. It gives info on husband, wife and their children. You'll also want a pedigree or ancestory chart. This will be your direct line only.
You want to learn all you can on each generation before you climb back up your family tree. A good foundation can save you the mistake of tracking the wrong branch of the family. Spelling of names can vary from record to record, also.
1880 census St Paul, Ramsey Co, MN:
Category: Name;Relationship to head of household; Marital Status; Gender; Race; Age; Birthplace; Occupation; Father's Birthplace; Mother's Birthplace.
Patrick MCNEARNEYSelfMMaleW41IRELANDLaborerIRELANDIRELAND Ann MCNEARNEYWifeMFemaleW40IRELANDKeeping HouseIRELANDIRELAND Michael MCNEARNEYSonSMaleW18VTBrakemanIRELANDIRELAND Mary MCNEARNEYDauSFemaleW16VTSeamstressIRELANDIRELAND Katie MCNEARNEYDauSFemaleW14VTSeamstressIRELANDIRELAND Cornelius MCNEARNEYSonSMaleW12VTAt SchoolIRELANDIRELAND Bridget MCNEARNEYDauSFemaleW7MNIRELANDIRELAND Annie MCNEARNEYDauSFemaleW5MNIRELANDIRELAND John MCNEARNEYSonSMaleW2MNIRELANDIRELAND Alosius MCNEARNEYSonSMaleW10MMNIRELANDIRELAND Honoria MCNEARNEYMotherWFemaleW87IRELANDIRELANDIRELAND
This gives you a family to play around with. This Patrick has a son named John, and if this should turn out to be your line, Patrick's mother is living with them, also.
Blooming Prairie is in Steel Co, MN. On the 1920 census Patrick is living with his married daughter, Anna, and her husband and children. Age for Anna fits the above Annie.
Now, none of this, so far, proves this is your line. You need to build your family tree and see if they do indeed fit.
Have you seen a copy of your father's birth certificate? It should give the name of his father, probably his age at the time of your father's birth and possibly his occupation. This would narrow down when John was born.
You state your father "was" Clifford McNearney, so I'm assuming he is deceased. On the TX Dth Idx there is a Clifford Raymond McNearney listed, died 18 Jul 1997 in Harris Co, TX.
If you live in that area, there is a great genealogy library in Huston, the Clayton Library. You might want to visit it.