New to WordPress

I downloaded the latest version, but have questions.

I played with it on my local server and wanted the online version to be only used by people I invite.

Once a person knows the main page address, you can skip the login.php for wordpress. That means they can see everything that was written.

I can password each page, but that would be a pain.

I used a 3rd party software called security assist for doing pages in Dreamweaver.

Is there a 3rd party software that will redirect a person if they tried getting to the main page without going thru the login page?

Please let me know if it’s possible. I have spent about 5 hours on this subject.

thx

Mike