To find help with Weebly SEO please view and go through the Weebly SEO Guide which has step by step comprehensive guide to understanding and hand holding through SEO maximization on Weebly.
This guide is the best tool we see success with on Weebly: https://www.weebly.com/seo

Complete the SEO Checklist outlined here: https://www.weebly.com/seo/checklist