The title of the video says:"The Signature Of J. R. R. Tolkien At Duckers Shoe Shop" But it seems that this is the manuscript of the seller. Does not look like the letter of Tolkien.
The year is 1913. So I think Tolkien was 21 years old. And bought "Black Football boots".
This is the ledger for the shoe shop, the clerks would have filled this in, not customers. It is probably a record that the young Tolkien owed them some money (looking at it again its states Paid 1st April 1914)
Even though Tolkien bought football boots I expect he used them for playing Rugby.