Short answers, pulled from the story.
Leopold Mozart presented a bound volume of blank music paper to his daughter Maria Anna on the 26th of July 1759. This gift marked her eighth name day and served as a pedagogical tool for learning keyboard music.
Wolfgang Plath deduced the existence of five scribes through paleographic study of the handwriting in the notebook. These included Leopold Mozart, Wolfgang Amadeus Mozart, and three anonymous copyists from Salzburg known as Anonymous I, II, and III.
Four of these pages remain lost while eight have been identified by Alan Tyson in global collections. Two pages reside in the Bibliothèque Nationale in Paris, one page exists in the Museum Carolino Augusteum in Salzburg, two pages are held at the Pierpont Morgan Library in New York City, and another page survives only as a facsimile containing opening measures of K. 5b.
Andante in C designated K. 1a was probably Mozart's first composition and consists of just ten measures. Allegro in F dated the 11th of December 1761 in Salzburg runs to twenty-four measures and is his earliest extant piece in F major. Minuet in F composed on the 11th of May 1762 represents his earliest work in minuet form. Klavierstück in C inscribed by young Wolfgang himself appeared sometime during 1764 as the first piece written directly by him.
Tables of intervals show that he introduced theoretical concepts immediately alongside practical playing. He also taught composition through given bass lines, melodies to be varied or continued, and structural models while combining technical exercises with modulating figured basses to build foundational skills.