Warning list in Dashboard after intstallation

Dear Support,
I have a problem – after installing Inovado Theme I have a huge list of warning signes in my WordPress Dashboard (please see screenshot – https://imgur.com/TxWtAk7 ). Moreover I can not use the left menu, as it is now hidden somewhere below.

Example of errors:
Warning: count(): Parameter must be an array or an object that implements Countable in /data02/virt74523/domeenid/www.euaccess.eu/htdocs/wp-content/themes/inovado/admin/functions/functions.mediauploader.php on line 127
Warning: Cannot modify header information – headers already sent by (output started at /data02/virt74523/domeenid/www.euaccess.eu/htdocs/wp-content/themes/inovado/admin/functions/functions.mediauploader.php:127) in /data02/virt74523/domeenid/www.euaccess.eu/htdocs/wp-admin/includes/misc.php on line 1126

After installation our the webste also looks very weird (looks like some elements are not shown correctly) – https://euaccess.eu/

Could you please advise me what could be the problem and how to solve it properly?
Thank you in advance,
Viktoria

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