How to access a page through dynamically friendly urls?

Well, I must be wanting something very complicated for a beginner but come on ...

I am starting a system where I need to create dynamic and friendly urls to register all the information about a page in the database and call this information when the page is accessed. The problem is that I do not know very well yet .htaccess . I ask for help !!!

  

htaccess

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteRule %{REQUEST_FILENAME} !-f
    RewriteRule %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)$ index.php?pagina=$1
</IfModule>

Question: How and what kind of relationship exists between the page and the content in the database so that when you call the url, come content. Something like this, if it is /index.php?page=contact calls the x content