1. If you want to stop the entire weebly site from Indexing, follow this step.
Your website automatically includes a robots.txt file that you can use to control search engine indexing for specific pages or your entire site. You can view your robots file by going to www.yourdomain.com/robots.txt or yoursitehere.weebly.com/robots.txt (using your unique site address in place of the examples, of course).
The default setting is to allow search engines to index your entire site. If you want to prevent your entire website from being indexed by search engines, go to the Settings tab in the editor and click on the SEO section. Scroll down to the "Hide site from search engines" toggle, switch it to the On position, and re-publish your site.
2. If you want stop certain pages from indexing, follow the following steps.
What if you only want to protect some of your pages from being indexed? Not a problem! You can do this for each page individually from the SEO Settings menu. First, make sure that the "Hide site from search engines" toggle shown above is set to Off. Then go to the Pages tab, click on the page you want to hide, and then on the SEO Settings button then check Hide This page from Search Engine