A soothsayer tells you to beware the ides of March
He's a dreamer. Let's leave.
Caesar tells Antonius to touch Calpurnia during the holy race because their elders say that if a woman gets touched during this holy race, they would be able to get pregnant and will be cured of the curse of infertility. Antonius agrees, and Caesar reminded him to not forget the rituals too. This part is important because it shows us that they value their beliefs and the sayings of their elders, and it also shows us that Antonious is loyal to Caesar.
I tell you, Cassius is dangerous...
A soothsayer walks up to him through the crows of people and informs Caesar to “beware the Ides of March”. The Ides of March is the fifteenth day of March. In this part, the soothsayer gives Caesar a warning. The soothsayer warns Caesar that he should beware the 15th of March and should avoid going anywhere on that day so to avoid any form of dangers.
Tell us what happened today that put Caesar in such a bad mood.
Brutus informs a confused Caesar that the man that spoke is a soothsayer. The soothsayer repeats his warning again to Caesar, but Caesar simply dismisses the warning and says he’s a dreamer. This shows that because Caesar dismissed the warning from the soothsayer, he believes he is invincible and cannot be defeated or beaten.
One more time and I'll accept
Caesar is suspicious of Cassius because he always holds himself seriously and goes on to say why Cassius should be feared and why he is possibly a dangerous man to be around. He says he doesn't smile very often, reads a lot, and is a good observer. As can be expected, he doesn’t like men growing bigger in status than him. He then tells Antonius to move over to his right side so he could hear him properly, for he cannot hear with his left ear--one of his humanlike flaws.
Caesar leaves, and then Brutus and Cassius ask Casca, who has been at the festivities with Caesar, why Caesar was in a bad mood as they are unaware of him having fainted due to his disease unknown to many, and what events took place.
Casca replies saying that a crown was offered to him three times by Anthony, but Caesar pushed it away--each time gentler than before; therefore, he would’ve eventually accepted it--and refused to wear it. And each time the crown was being offered to Caesar, the crowd cheered, presumably for Caesar's humility. Casca, however, seem to be not a reliable source for he doesn’t seem to have been paying attention very well.