As it happens, I am currently looking for a computer course for myself and I would like to join one of your courses.

as 在这里是连词，表示"正如、如同"的意思，引导方式状语从句。 it 是代词，指代后面提到的整个情况或事实。 happens 是动词 happen 的第三人称单数现在时，意思是"发生、碰巧"。 as it happens 是一个固定短语，意思是"碰巧、恰巧"，用来表示某事的发生是巧合或偶然的。