The fastest way is to look for the current copyright text inside your theme’s footer.php file and substitute it with something more of your liking.
My suggestion, as I don’t know what you mean for “dynamic”, is to substitute the current text with a function call, like <?php my_copyright_text() ?>, and then define that function in your theme’s function.php file in which you do whatever you need to do.
function my_copyright_text(){
$year = date("Y",time());
$company = "Mycompany.com";
echo "© 2018-$year $company"; //this is effectively HTML code
}
As the output of the function is HTML code you can insert tags and css classes as you like. For example "© 2018-$year <span class="company">Mycompany.com</span>".
It is strongly suggested to use a child theme, as not to let theme updates overwrite your tweaks.
If you feel brave you can put some of the parameters in the theme customizer, take a look here.