WordPress.org

Can I translate myself, or do I need to pay for it?

You can certainly translate your site yourself. The professional translation is an optional feature intended for people who don't want to translate themselves.

If you're translating your site yourself, just ignore that option.

Everything in the theme still appears without translation

Have a look at this theme localization guide.

Languages per directories are disabled

To be able to use languages in directories, you should use a non-default permlink structure. Also, go through the detailed description.