* The Soothsayer's warning: In Act 1, the Soothsayer warns Caesar to "beware the Ides of March." Though Caesar dismisses him, the fact that he is aware of the warning and even acknowledges it ("He is a dreamer") implies a level of awareness, perhaps even a touch of concern, towards the omen.
* Calpurnia's dream: Calpurnia has a vivid dream about Caesar's statue bleeding, which she interprets as a bad omen. This dream, while not Caesar's own, is presented to him as a sign, and his initial reluctance to go to the Senate could be interpreted as a superstitious response to her anxieties. However, he ultimately overrides his concerns and decides to go.
* Caesar's dismissive attitude: Throughout Act 2, Caesar repeatedly dismisses omens and warnings. This could be interpreted as a way of demonstrating his confidence and control. However, it could also be seen as a cover-up for a deeper belief in the power of these signs, especially in light of the other examples.
It is important to note that Shakespeare never explicitly states Caesar's belief in omens. The interpretation of these instances is left open to the audience. However, these scenes do hint at the possibility of Caesar being at least aware of the power of omens and perhaps even holding some degree of superstitious belief.