Blocksy Theme errors

We just installed WP 542, running php 7.4, theme Blocksy. However when we tried to install this plugin – it came up with a number of errors. Still seems like it installed but the errors are still visible at the top of the screen. I’m pretty new to WP, was wondering what I did wrong? I installed about 10 other plugins without any issues, but this one showed errors.

Here’s what the errors at the top of the screen looked like when I clicked on Plugins/Activate:

Deprecated: The behavior of unparenthesized expressions containing both ‘.’ and ‘+’/’-‘ will change in PHP 8: ‘+’/’-‘ will take a higher precedence in /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php on line 76

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-includes/functions.php on line 6221

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-includes/pluggable.php on line 1281

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-includes/pluggable.php on line 1284

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-admin/includes/misc.php on line 1282

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-admin/admin-header.php on line 9

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-includes/option.php on line 961

Warning: Cannot modify header information – headers already sent by (output started at /home/sammtg/public_html/sm/wp-content/plugins/shortcode-for-current-date/shortcode-for-current-date.php:76) in /home/sammtg/public_html/sm/wp-includes/option.php on line 962

I contacted the Blocksy theme support and they couldn’t help, but the plugin didn’t work with 2020 theme either.

Sounds like it might be something simple, but I don’t know how to fix it. Thanks much for your help with this!