The first cards that I bought was 1965 Topps. I had a shirt covered with iron ons.
The first set I tried to complete was 1967 Topps. I had the first six series complete, but never saw 7th series in a store. I bought the 7th series a few years later from Card Collectors Co.
The first set I completed by busting packs was 1968 Topps. I would go to the local stores every week and buy a pack. If it was the new series, I would buy a whole box and trade for any cards that I needed.