The first album I ever bought was The James Gang, Rides Again when I was 14 (it had already been out for four years).
I don't recall what the first 45 was.
Edit:
Ok...now that I think about it...I asked for and received, for my sixth or seventh birthday...are you ready for this?...
Herman's Hermits, I Henry VIII, I Am.
My taste in music improved just a touch over those eight years...actually music improved by leaps and bounds in that timeframe...only to go back downhill during my high school years into the deep dark recesses of Foreigner, Journey, Styx, etc. By then rock was simply following the money and no heart and soul remained.