The driving in Egypt is very different than in the US, they treat it like bumper cars. We recommend Uber or taking cabs as it is considerably cheaper after doing the conversion rate.
There are places in Cairo where you can exchange cash for Egyptian currency (EGP) such as Banque Masr or other banks. I recommend while you stay in Egypt to mainly use EGP as can be cheaper than using any type of card. You can still use your card and will be considerably cheap but bring cash just in case. The exchange rate is constantly changing but as of recent 1 American dollar is equivalent to 50 EGP.
Ultimately it's a matter of comfort, there a lots of apartments available for rent as an Airbnb and hotel stays that are on the affordable side.
When you get into Cairo Airport you'll have to go through customs and pay for a visa and they take cash only. It's roughly $35 for the Visa. You'll have to explain why you are visiting you can simply just say tourism.