Where a freelance copywriter should submit articles to promote himself

To elaborate on this point, below you'll find the definition of copywriting as defined by Wikipedia.

The only reason we're emphasizing this is because presenting yourself as a copywriter when you're actually a content writer is misleading and would be considered a bit of a false advertisement by many online marketers - actual sales copywriters, especially, get really annoyed.

As an aside, learn copywriting if you have the time - it's where the real money is as far as writing services go. That said, it's a specialized skill that takes some focused study to develop.

Edit: All links in the text below are Wikipedia's own links - nothing shifty going on here.

Copywriting:
Copywriting is the act of writing copy for the purpose of marketing and advertising a person, business, opinion or idea.
The purpose of marketing copy, or promotional text, is to persuade the reader, listener or viewer to act—for example, to buy a product or subscribe to a certain viewpoint.
Copywriters (as writers of copy are called) are used to help create direct mail pieces, taglines, jingle lyrics, web page content (although if the purpose is not ultimately promotional, its author might prefer to be called a content writer), online ads, e-mail and other Internet content, television or radio commercial scripts, press releases, white papers, catalogs, billboards, brochures, postcards, sales letters, and other marketing communications media.

This is also why 'content writer' posts and related comments are not allowed on the Copywriters subforum.
_____
Bruce