I am create a new in wordpress blog. but i don't know How to Install Google Analytics in WordPress Blog?
Dashboard * Plugins * Add New Plugins, search for Google Analytics. There will be plenty on there, you can choose any one that you like. Or edit your theme's header.php, look for something look like </head> (there will be only one), and put your GA script right before that. Note that some people prefers to put the script into footer, not header. If that's what you want, edit your theme's footer.php and put your GA script right before </body> (again, there is only one closing tag so you won't miss it).
Don't edit your actual theme as any changes you make will be lost next update - Never ever edit main code, always use a child theme for any editing of php or css. That way when the theme is updated you changes will still be there.
i wasn't trying to undermine you advice, just reminding that a child theme is needed. No offence intended
If you don't want to add plugin then get the analytics code and go to Appearance > editor then in editor open header.php and place your analytics code there. That's it.
If you have Cloudflare enabled on your website, you can go to Apps in your Cloudflare Dashboard and add it from there. It's cool because you don't have to edit anything in your template or use a resource eating plugin. Just saying