For tips on language learning and learning Egyptian Arabic specifically, see this post and this post.

What's the difference between Standard Arabic and Egyptian Arabic?
Egyptian Arabic is the dialect used by 80,000,000 Egyptians in everyday life, at work & with family, while Standard Arabic is the language of literature, newspapers & pan-Arab media. Standard Arabic isn't spoken on the streets in any country - the Lebanese have their own dialect, the Libyan have theirs, the Iraqis have their own dialect and so forth with all the Arab countries.
Egyptian Arabic is one of the most popular dialects to learn because of the popularity of Egyptian films, music and also because Egypt is a huge cultural center within the Middle East.

Will other Arabic speakers understand me if I speak Egyptian Arabic?
Egyptian Arabic is one of the most widely understood forms of Arabic.

What do all the numbers in the words mean?
3 - ع The sound close to "a" which occurs at the beginning of words such as 3arabi (Arabic).
7 - ح A very strong emphatic "h" coming from the Adams apple. (Or Eve's apple!)
5 - خ A sound similar to that in Scottish "loch" coming from the throat. Can be seen in words such as "sheikh"
2 - ع or ق A sound that occurs before saying words in English such as "arm". A glottal stop. Like cockney "bottle" when the T's aren't pronounced rather insinuated with a sharp glottal stop. Can be seen in Arabic words such as 2alb (Heart).