Same time as tackle football, when a player gets in the end zone with the football, but usually its not a rushing touchdown in flag football.
The goal of football is to move the ball down the field and into the end zone for a touchdown.
boo who
yes
yes?
Another football is brought out to continue gameplay.
Nothing. This happens more than you may think. Many players keep the football when it is a particularly meaningful touchdown to them (like their first or a record breaking touchdown).
Thermal
any player on the offensive team
point after touchdown point after touchdown
when a player makes a touchdown from the 30 line (3=triangle)
The origins of American football began in 1869. The intercollegiate football game between Rutgers and Princeton took place at Rutgers in 1869. There is no record of what player scored the first touchdown.