Start with multi-site feature now or later?

Start right now with multi-site, before you add content. Moving content from a former single site to multi-site on the same domain is not exactly a seamless process.

And yes, subdomains are one of the features of a multi-site setup.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)