How many chances does the offense get to reach a first down?

According to the webpage from dummies . com :

"If the offense has failed to advance 10 yards after three tries, the team usuallypunts the ball on the fourth down (a punt is a kick to the opponent without the use of a tee). The other team then begins with its own set of four downs, traveling in the opposite direction."

I hope my answer has come to your help. God bless and have a nice day ahead.