Site logo not showing up on google

What site icon?
and
What part of Google?

If you mean your business listing image, this is not a WordPress issue. You need to add it to your business profile:
https://support.google.com/business/answer/6103862?co=GENIE.Platform%3DAndroid&hl=en

What I mean is my site logo is not showing when you search for my blog on google.

You can click on the link above to check the picture of what I’m saying.

This is still not a WordPress issue.
You need to generate the icons and implement the markup and add it to your header.php file.
See here:
https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariWebContent/ConfiguringWebApplications/ConfiguringWebApplications.html#//apple_ref/doc/uid/TP40002051-CH3-SW4

You can generate the files you need to upload, and the markup here:
https://realfavicongenerator.net/