Unwanted links in google index

You could do this with a robots.txt file.

Also, wp-admin should NOT be getting indexed at all.

You can use this plug-in (https://yoast.com/wordpress/seo/#utm_source=wpadmin&utm_medium=plugin&utm_campaign=wpseoplugin) too. It will give you the option to allow the page to be indexed via a check box on the posts and pages. Once installed look for the Advanced tab in the SEO section of the page/post.