There is, but it's not used in the same way as it is in English. When describing someone or something now, it's not used. If we want to talk about how someone or something was in the past, we do use it. For example:
"Bob was a doctor" = بوب كانَ دُكتوراً
In this case, كانَ is the verb "to be" in the past tense, and its presence makes us add the اً at the end, which is pronounced -an (but it's ok if you drop that sound, we often do that when speaking or reading).
Having said that, the order of the words is more flexible in Arabic, and it's actually more natural to say:
كانَ بوب دُكتوراً
Yes it is. Arabic is the opposite of English in this term (noun - attributive adjective). So, there is منعوت (noun, which is described by adjective) comes first, then is followed by نعت (attributive adj.).
But, in this sentence, there is no attributive adj.
Bob is a doctor: بوب دكتور
Bob is a subject while a doctor is a predicate.
There are, but my knowledge is too limited to explain this to you. Maybe you can learn something from this.... https://blogs.transparent.com/arabic/indefinite-nouns-and-definite-nouns-in-arabic/
(and there are certainly more of these sites to be found ... google for "definite indefinite article arabic" and you will definitely find information. Hope this helps a little.