Most fans at one soccer game?

Answer 1

At the start of a soccer match with a full complement for each team, there are two sides of eleven and the referee for a total of twenty three.

Side one: 11 Side two: 11 Referee: 4 (11 + 11 + 1 = 26)

In some cases, there may be a "short-sided" game where a reduced number of players take to the pitch. But per the FIFA guidelines, the posted numbers are correct.
11 players total 10 field players and 1 goalie
Each team is allowed to have 11 players on the field at a time, 10 outfield players and a goalie. This means there are 22 players on the field at a time.

Answer 2

Brazil - Uruguary on July 16, 1950 at the Maracana stadium (199,854 in attendance)

Answer 3

5