Emergency assistance database connection

[Binsu]

Hello, I moved a website from one host to another. I created a new database, made the necessary adjustments, and ensured that the passwords are correct. However, I'm encountering the following errors: Is there anyone who can help with these errors?
Warning: Cannot modify header information - headers already sent by (output started at /home1/iceays/public_html/wp-config.php:1) in /home1/iceays/public_html/wp-includes/functions.php on line 3588
Error establishing a database connection
Related website: www.compay.com.tr
Assistance is appreciated.