Shakespeare was not trying to warn Caesar who died 16 centuries before he was born.
Are you asking what the dramatic effect is of the warning Caesar receives from the soothsayer and from Calpurnia?
Dramatically, Caesar's reaction to the warnings may show him to be conceited and arrogant (or confident and level-headed, if you like him).
To warn Caesar to beware of the Ides of March.
"Beware the ides of March"
The Soothsayer had already cautioned Caesar about the ides of March but Caesar again paid no attention to it saying that the soothsayer was a lunatic and was hindering his way. Then on that very day when Caesar said very confidently that the Ides of March are come, he replied that it wasn't yet passed. This was a clear warning to Caesar about being prepared for any worse circumstance in future. But, as pride hath a fall, the same way Caesar went on with the days activities too confident about his security thinking that no one could ever harm him. Artemidorus had written a letter of precaution for Caesar in which he had mentioned the names of all the conspirators but failed to deliver it to Caesar because he said to him to read his petition first as it concerned Caesar personally. So, Caesar refused it saying that which considers him first shall be dealt with at the last. These warnings were over looked by Caesar which paved the way for his death.
"The Ides of March are come.""Aye, Caesar, but not gone."The audience knows that the plot the soothsayer is warning Caesar about is real, even if he doesn't see it. He is like Bud Abbott, being calm while Frankenstein's monster lumbers up from behind him. And Lou Costello, who sees the monster and tries to warn Abbott, is the soothsayer, who gets pooh-poohed for trying to warn him. (If you don't know who Abbott and Costello were, look them up. It's worth it, believe me.)Caesar is all smug because he thinks the soothsayer was wrong. The soothsayer, and the audience with him. know that he is not out of the woods yet.
Two people. Artemidorus, the guy who tries to warn Caesar about the conspiracy, signs his letter of warning to Caesar "thy lover, Artimedorus". Brutus, also, in his speech to the people says "as I slew my best lover for the good of Rome, I have the same dagger for myself", referring, of course, to Caesar.
In Shakespeare's play Julius Caesar, Caesar is murdered in the Senate at the begining of Act III. Caesar's ghost later returns to warn Brutus that he will die at Philippi - a warning that Brutus seems neither surprised, nor much troubled by.
To warn Caesar to beware of the Ides of March.
give Caesar a letter to warn him about the sonspirators plan
Artemidorus is important because he is trying to warn Caesar of the conspirators and that Brutus is planning against him. He writes a letter to tell him and Caesar does not accept it before going into the Senate.
If you mean in the play Julius Caesar, I don't know. If you mean in reality, no, he didn't warn Caesar because he didn't know anything about the conspiracy.
give Caesar a letter to warn him about the sonspirators plan
The soothsayer wishes to see Caesar pass on to the Capitol to fulfill his warning from earlier, where he cautioned Caesar to beware the Ides of March. The soothsayer believes in fate and is concerned about the consequences of ignoring his warning.
Artemidorus writes a letter to Caesar In ACT II, SCENE DIII
He is trying to warn Caesar of the assassination plot.
In Shakespeare's "Julius Caesar," Marcellus is a Roman senator and a supporter of Pompey. He appears early in the play during the opening scene, where he expresses concern over the political climate in Rome and the rising power of Julius Caesar. Marcellus is notable for his role in trying to warn the public about the dangers of Caesar's growing influence. He famously declares, "Who else would soar above the clouds?" highlighting his apprehension about Caesar's ambitions.
Letter from Artemidorus
"Beware the ides of March"