About WordPress site security

If I install WordPress on my server, does it mean that Akismet is installed automatically?
If so – do I still need to create e-mail verification and captcha tools for improving site security (as I see WP does not have this features in itself).
What is recommended for captcha test- simple php captcha or some graphical ajax invention (by drawing or moving objects etc)?

My site will be rather plain, but will have user’s comments on each page.

Akismet comes pre-installed with WordPress. You will, however, need to activate it from the ‘Plugins’ menu and sign up for an API key (free plans are available).

And no, captchas are not needed (Akismet catches almost everything), but you can find a plugin to add one if you wish.

If you’re concerned about sercurity, I recommend the Better WP Security plugin.