Egyptians speak their own dialect of Arabic, and if you can master some basic phrases, you will be extra welcome. But most people in places where tourists are seen do speak English and many will also speak some French and German and, to a lesser extent, some words of Chinese and Russian. If you are booking a guide to visit tourist sites, for instance, you will have a choice of all these languages.
Studying Arabic in Egypt is popular because the dialect is understood throughout the Arab world, and classes are plentiful and inexpensive. You’re entitled to a student visa only if enrolled at an accredited university such as the American University in Cairo (AUC), so bear in mind the need for extending your tourist visa.