I was about to start learning the Saudi Arabian dialect of Arabic, but I really dont know now. Egypt has a higher population count and could have more opportunities and I have more Egyptian friends so I'm thinking of Learning the Egyptian dialect. Let me know your thoughts.I will make videos in Arabic once I get better too so please let me know your thoughts on Which dialect I should learfn of those two. And, is written Arabic the same and not different for each country?
I would reconmend learning to speak Modern Standard Arabic and if you want <em>only understand</em> the local dialects of where ever you want. This would be the most efficent method to be able to speak with the most amount of people.
I would go with Ahmad's recommendation of learning the Modern Standard Arabic (MSA) this will give you the foundations of Arabic language. Dialects could be learnt through social engagements/communication depending on your social activities, i.e hanging out with Arabic friends, folloiwng the media/entertainment online channels of certain region, future plans..
Once you learn the foundations of MSA then you will be able to catch dialects. Saudi/Gulf states dialects are very different than any other dialect in Arab region, and so goes for most of Arabic dialects. Egyptian dialect will be easier to grasp than Saudi.
Formal writing in Arabic is the same across the Arab region, but the dialect/informal writing is different, and usually it takes time to acquire this writing skill such as in any other language.
I would strongly recommend learning the basics of Modern Standard Arabic (MSA) before you dabble with any particular dialect. MSA is understood by most Arabs, regardless of which country you are in so it will be easier to communicate with more people in a short space of time. It's also the backbone of the dialects, so you will learn bits and pieces of many dialects at the same time (with varying grammar and pronunciation).
It's not the language of daily life, so you will have to learn a dialect eventually if you wanted to travel and not stick out like a sore thumb. I regularly get reminded that I speak "like they do in the cartoons", when I speak MSA. Although it sounds funny to them, it doesn't stop them from understanding me.
I also started learning Arabic recently. I'm learning Modern Standard Arabic, so no particular dialect. That is also the written Arabic for all regions, as far as I know.
I've been told that traditionally, Egyptian productions have dominated the media. That's one of the reasons why the Egytian dialect is easy to understand for almost all Arabic speakers. So unless you have some connection to Saudi Arabia, the Egyptian dialect might be a good fit for you.
Learn whatever dialect you like. It isnt about the amount of people who speak that dialect, because most arabs can hardly understand other dialect. As a jordanian I have a hard time understanding iraqi and saudi arabian dialects, but I can understand levantine dialect. So see what you like most and go for it.