How do I get good free WP plugins?

Wordfence Security - It is the firewall and malware scanner for WordPress, that blocks malicious traffic, check files for malware, and scan file contents, posts and comments.Yoast SEO - The plugin help WordPress site with the SEO

Personally I advise to give a try these wordpress plugins download https://monsterone.com/wordpress/wordpress-plugins/ for example. It is very easy if you have skills for it. I think you will be able to do it yourself ;) Plus mind that it is the richest resource of some unique themes and you can stand out quite easily. Good luck