What is the best way to remove old site from Google

Hi.

I have purchased a new domain and published several posts. Later I found that this domain already registered few years back and probably it was penalised by Google for spam.

What I want is how do I remove that site completely from Google and use already published posts in new site?

Old site Google crawled but not indexing. So I want to use the old site posts (written by me) and start a fresh site. If I use the old site posts is it make duplicate content issue?