I just downloaded and installed XAMPP and WordPress to be able to create and edit my websites in my local machine, but I have a problem. In the WordPress installation process I was requested to create a new account, so I did. The thing is I already have a WordPress account. The newer one that I created, I did with the same email than this one. I don't want to use the new account, I want to use my previous one to continue to work on the sites I've already created but when I try to log in at localhost it doesn't recognize it. The only one it recognizes is the one that I created in the installation process. How can I log in WordPress at localhost with my previous account?
WordPress do not work like Facebook or Twitter. Each WordPress installation is a separate application, it has its own database where users are stored, each installation is independent of one another. Your localhost installation of WordPres has no connection to the one on the server they are two entirely different entities.
But you can copy all contents from your server to your local installation, it is called migration. Here is a very in-depth guide on how you can do that: https://premium.wpmudev.org/blog/moving-wordpress-site/