If you need advertisers for your website, you might want to read How to Make Money From Your Website and the follow-up article How to Increase Your Website Revenue from Affiliate Programs. A list of advertisers and affiliate programs can be found on Affiliate Programs: Free Sponsors and Advertisers. Those companies are on the constant lookout for new web publishers to display their advertisements.
All of the web services listed here have you start by choosing from a selection of templates for your site. The better ones, such as Duda, Squarespace, Weebly, and Wix, use templates that automatically reformat your site for viewing on mobile devices. They also offer specifically targeted templates based on your site's purpose, such as for promoting a bakery's sales, getting gigs for a musician, or keeping wedding guests informed.