Wordpress Install Help

Hello - I am installing Wordpress but keep running into problems. The install appears to work successfully but I visit the domain.com/wp-admin page it says there is a critical error. I have attached a screenshot.

I need someone who can help me overcome this issue so I can login to the Wordpress dashboard and begin working on my client's site.

The error appears to be a PHP error, but I'm not 100% sure.

If anyone can please help as soon as possible I will appreciate it!

Many thanks
Oliver