The Romans had many different kinds of entertainment. There were other things besides gladiators and theater. Often people had parties that had dancers or musicians. Some people did not have enough money to go anywhere, so they watched people on the street.
Gladiators were slaves or prisoners of war who were forced to fight and kill each other. Gladiator battles were religious in origin, first held at funerals to honor the dead slaves, the gladiators.
There were 6 kinds of gladiators: Samnite, Hoplomachus, Thracian, Mirmillo, Retiarus, and Secutor. There may have been some unknown gladiators. Two of the different kinds of fights were the Naumachia and the Venatio. A Naumachia was when the arena was filled with water and teams of one kind of gladiator would be on boats and they would try to sink enemy boats. A Venatio was when wild, ferocious animals were let out to fight the gladiators.
The Romans started theater very late compared to other countries. Rome started theater in the third century BC, and even then, most of the things were taken from the Greeks, who started theater in the fifth and sixth centuries BC. Later, in the second century BC, some Roman playwrights, particularly Platus and Terence, became very popular.
Mimes and pantomimes were also very popular. Mimes were actors who did comic skits much like some TV shows today. The pantomimes were performed by a dancer who was accompanied by musicians and a choir singing the narration. Pantomime acting was more serious than mime acting.