I use EasyPHP and installed only it, PhpMyAdmin works perfectly and I can perfectly manipulate the tables.
Is the MySQL installation already built into the localserver that I use or something like that? Do I need to install any other software to perform better?
EasyPHP installs everything you need to learn how to use a web server, including MySQL. You do not need anything else, although you may want other things later.
With learning you will know what can help you the most and will make you no longer want to use this kind of bundle software. It is great for helping those who know nothing, but it sucks for normal use. It facilitates the use just by hiding what can give more performance and flexibility.
I suggest that you focus a lot on everything that was installed to start learning a little more deeply how it works and then take the step of not needing this type of software and have more control over what you are using. Curiosity is key to evolution.
PhpMyAdmin is just the MySQL database administration interface. You can verify that the EasyPHP installation folder has the MySQL folder. But nothing prevents you from installing MySQL Workbench (which is the well-known MySQL, when in fact it is also just an interface / database administration tool - works similarly to SQL Server Management Studio which is the SQL Server tool, where "management" means "management" or "administration").
A database management program does not come with the EasyPHP installation package or another server program, such as Wamp, Xampp, and Apache.
You can download a program that manages a database. Some of them:
