New iMac will not connect to current Wi-Fi ? Why?

Read: If your Mac doesn't connect to the Internet over Wi-Fi - Apple Support, If you can’t connect to a Wi-Fi network on Mac - Apple Support, and Troubleshoot joining a Wi-Fi network on Mac - Apple Support.

Also, reset:

• PRAM: Reset NVRAM or PRAM on your Mac - Apple Support.
• SMC: How to reset the SMC of your Mac - Apple Support.

If it still does not work, try joining in Safe Mode (Intel): How to use safe mode on your Mac - Apple Support.

Cheers,

Jack

Not enough information to answer.

Please provide the error message you're getting.

Also, please provide year of your iMac. By "new", I'm assuming it's the late 2020 27" iMac correct?

Are you connecting to your home WiFi? Are you seeing the home SSID WiFi network? Is it not accepting your password?

What model WiFi base station are you using?

Hi LarGeR-man,

What error are you seeing?

Cheers,

Jack