Macbook pro 15 2017 will not connect to the internet, wifi or hardwired

Restart your router/modem.

Startup in Safe mode. https://support.apple.com/en-gb/HT201262 Choose the appropriate method.

To leave Safe Mode, choose “Restart” at the bottom.

Deselect Proxies, if selected.

   System Preference > Network > Advanced  > Proxies Tab

   Unlock the lock if you have to.

   Under "Select  a protocol…”, uncheck any box if check-marked.

   Click "OK” then  "Apply”.

Quote:

For example, Safari can’t open a website that uses a protocol other than http or https.

https://support.apple.com/guide/safari/if-you-cant-open-a-website-ibrw1071/mac

Try suggestions given in this article.

https://support.apple.com/guide/mac-help/if-you-cant-connect-to-a-wi-fi-network-on-mac-mchlp1185/mac

See also

Show Wi-Fi status in the menu bar on Mac

Troubleshoot joining a Wi-Fi network on Mac

Apple Support article: If your Mac doesn’t connect to the Internet over Wi-Fi

Apple Support article: Recommended settings for Wi-Fi routers and access points

If you manually enter numeric IP address 1.1.1.1 do you get the CloudFlare splash page?

If you do, you can see numeric IP addresses, but there is a problem in looking up alphabetic addresses. You likely have a DNS issue.

CloudFlare is NOT part of the solution here, they just have the absolute simplest IP address that is known to respond with a web page.

Can you please post an EtreCheck report?

 Download EtreCheck: https://etrecheck.com/  and post the report here.

 Click, “Free Download” button and then  “Click to download” button,

 open Downloads folder, click on it to open, and then select ”Open”.

 Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.

 Click “Share Report” button in the toolbar and select “Copy report”.

 Click the “Page” button in the toolbar at the bottom of this page and paste it when you reply.

 Note: This is a diagnostic test.