I pref 'all in one seo' vs yoast. but both will do the job.
Yoasts free version has had some issues in the past for me
these plugins arent automatic though they do require work. but a seo plugin is a must!
all in one seo:
https://wordpress.org/plugins/all-in-one-seo-pack/
yoast:
https://wordpress.org/plugins/wordpress-seo/