Site crashes after updating to php 8.0

I am trying to update my site to php 8.0. It keeps crashing and giving me the white screen. I deactivated all plugins and wouldn’t come back. I then changed the theme to WordPress default theme, twenty twenty-three, site comes back up. Re-Activated Shopical Pro and site crashes again and gives me white screen. Ran debug mode and got following which I don’t know what it means or where to start.

Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function “my_theme_enqueue_styles” not found or invalid function name in /var/www/wp-includes/class-wp-hook.php:308 Stack trace: #0 /var/www/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #1 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #2 /var/www/wp-includes/script-loader.php(2180): do_action(‘wp_enqueue_scri…’) #3 /var/www/wp-includes/class-wp-hook.php(308): wp_enqueue_scripts(”) #4 /var/www/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #5 /var/www/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #6 /var/www/wp-includes/general-template.php(3043): do_action(‘wp_head’) #7 /var/www/wp-content/themes/shopical-pro/header.php(20): wp_head() #8 /var/www/wp-includes/template.php(783): require_once(‘/var/www/wp-con…’) #9 /var/www/wp-includes/template.php(718): load_template(‘/var/www/wp-con…’, true, Array) #10 /var/www/wp-includes/general-template.php(48): locate_template(Array, true, true, Array) #11 /var/www/wp-content/themes/shopical-pro/page.php(15): get_header() #12 /var/www/wp-includes/template-loader.php(106): include(‘/var/www/wp-con…’) #13 /var/www/wp-blog-header.php(19): require_once(‘/var/www/wp-inc…’) #14 /var/www/index.php(17): require(‘/var/www/wp-blo…’) #15 {main} thrown in /var/www/wp-includes/class-wp-hook.php on line 308

If someone could help me I would really appreciate. I am developing my own site and am mostly self taught but havent learned php yet at all.

Thank you

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