Creating wordpress multisite network

I require advice on what plugin would suit best for my problem.

I have a website developed on Wordpress classic and need to convert it to a network multisite. So I will need multiple onepage microsites that can be deployed from the main website admin on subdomains. So there would be, etc. What would be the best plugin to use from your repository?

Please advise as soon as you can.

Thank you.
Valentin Acatrinei
Bamsboard ltd.