One of the best known websites for tips and tricks for Search Engine Optimisation is making a dozen or more training courses available for free until May 31st 2020.

Go to: You Can Now Take Moz Academy Courses for Free – Moz

If you are new to SEO, check out their excellent article: https://moz.com/beginners-guide-to-seo

This guide is designed to describe all major aspects of SEO, from finding the terms and phrases (keywords) that can generate qualified traffic to your website, to making your site friendly to search engines, to building links and marketing the unique value of your site.