Multiple WP accounts

A long while ago (4 years) I created a WordPress account to try and create a new product website. This was abandoned soon after. I can no longer login to the WP account I created and my user name (e-mail) isn’t recognized.

About the same time I created a separate login to this WP user forum. Even though the same time frame has elapsed, I logged in fine today.

More recently (last year) our appointed web developer built me a new website (http://www.totallockout.com) and gave me a new login which enables me to edit the site.

Now I want to create a brand new website on a new URL domain. I don’t have wordpress software on my PC. Do I need it or is it all web based?

How should I begin? Thanks for any assistance.