Rand's philosophy was sophomoric. She claimed to be a student of Aristotle, but there is little evidence of it in any of her writings. How do I know? I'm embarrassed to admit that I went through a Rand phase in my twenties. But she did interest me in Aristotle, who then interested me in St. Thomas.
Thomistic Philosophy is a great introduction to Aristotelian philosophy. This handful of pages is worth more than a modern college education, since it deals with first principles.