Expired domain since 2012, still in index

Hi, I would like to have some guidance about a domain a just ordered, it seems that the domain is expired since 2012 but when i run the site:domain.com command there is still pages on the google index, what should I do?
Is it bad for the future of the domain name?

I'm asking because before that, for the same website i had a domain who had like 120 whois records change in 2 years (noticed that after), and for 1 month the site had 0 evolution in serp/traffic despite all the seo i've done on it, that's why i got a new domain.

Thanks

any thoughts?

I'm not sure about that point, but what I will do is to explore the website link profile and see if it was linked from strong unspammed websites then I will definitely go for it.