Integration with existing site

I have a Blog site built from scratch by myself but with no place for others to post comments etc. Can wordpress pick up the code of https://www.mooseblog.co.uk and just let me add posts as and when without me having to edit my sourcecode?
Also, how easy is it to set up a comments section and what will i need from my hosting provider?

thanks (couldn’t understand much of the techy stuff provided by wordpress)