Arabic has many fonts, so you don't have to learn calligraphy. It's enough to memorize the alphabet and learn how to write it correctly. Learning Arabic in English letters and numbers is possible, but it's not a good choice, in my opinion. Reading Arabic written in English letters isn't easy as you may think. Because if you write in Arabic letters, each word has a fixed spelling, but in English letters you'll find the same word written using different spelling. I think it's difficult to memorize the words in this way.