I translated your message using Google Translate:
Hello, I recently created an account on WordPress but the Panel does not display the Install Plugins button, because I wonder if it's a problem in WP or if it's because I need to do some updating. How to buy a domain or be a Premio user.
WordPress.com has a lot of built-in features that were inspired by popular plugins. Chances are, the feature you are looking for is already there! You can search our support site via this link:
For any features on WordPress.com, the support page will explain how to set it up.
However, it is not possible to install plugins on WordPress.com, for security reasons. Plugins can only be installed on self-hosted WordPress blogs. If you are wondering how WordPress.com differs from WordPress.org, this support article explains the distinction: WordPress.com and WordPress.org
If you don't find what you are looking for, just let me know what you'd like to achieve with a plugin, and I'll help you find a solution.