Yes, it's correct, but we tend to only use 'much' after 'how', 'so', 'too' and in questions and negatives.
We don't generally use 'much' in straightforward statements. So, while "I have much information" is technically correct in grammatical terms, a native speaker of modern English would never say this.
We would normally say, for example, "I have a lot of information" in informal contexts and "I have a large amount of information" in more formal contexts.