New MacBook Pro m5 can't connect to the internet

Start here. There is a diagnostic tool that can be used to identify several issues. One may be a DNS problem or that you have VPN/Antivirus software installed on your Mac and that is blocking internet access.

If your Mac isn't connecting to the internet over Wi-Fi - Apple Support

I assume you are using able to access the Internet using the same WiFi with your iPhone. You may need to turn off Cellular Data to verify that WiFi is actually being used. Having a WiFi connection and Internet access are 2 completely different things. If certainly is possible to be connected to a router over WiFi where you will see the signal strength connection in the menu bar, and the router not having internet access. In that case restarting the router may allow it to connect to the internet again, or there may be an ISP problem.

Great! Thanks for the update.