How do the workmen celebrate as the play begins? the tragedy of julius caesae by william shakespeare

They celebrate Caesar's victory at Pompey through statues, decorations, etc.
The Tragedy of Julius Caesar is a tragedy by William Shakespeare, believed to have been written in 1599. It is one of several plays written by Shakespeare based on true events from Roman history, which also include Coriolanus and Antony and Cleopatra.
Although the title is Julius Caesar, Brutus speaks more than four times as many lines, and the central psychological drama of the play focuses on Brutus' struggle between the conflicting demands of honor, patriotism, and friendship.

Farewell Address