How to Install Theme, Plugin and fix Upload Max FileSize Error

what if you get an error like this " Fatal error: Declaration of Auxin_Walker_Nav_Menu_Front::walk($elements, $max_depth, $args = null) must be compatible with Walker::walk($elements, $max_depth, ...$args) in B:\wampserver64\www\wordpress\wp-content\themes\phlox\auxin\auxin-include\classes\class-auxin-walker-nav-menu-front.php on line 394" how do you solve it

Sir,
Where did you get the themes from?

Please where is the link to the next Video..?

Could you please suggest some matrimonial or dating themes ?

just want to ask what plox and elementor differ on default wordpress theme?