My very first song I learned was "Where is Thumpkin" and it required the use of all of my fingers using parts of the c Major scale.
Mary Had A Little Lamb and Twinkle Twinkle were not far away.

The first real song I ever mastered was Iron Man...solo and all. Then I moved onto Mr. Crowley and Crazy Train.

.......Aaaaawwwww the memories........

I still play everything listed till this day...lol