When you install WordPress for the first time, it can be very confusing to pick and choose what plugins will be needed. I have many WordPress installations and I have the below free plugins in all of them and these plugins have been supported for more than 5 years and current too.
Prevent Spam : Spam is a big problem. You should have this Akismet Plugin to stop spam. Akismet Anti-Spam by Automattic
https://wordpress.org/plugins/akismet/ . You will need to have wordpres.com account to get a free key to use it. It works very well.
SEO : Yoast SEO is the most popular Search Engine Optimization plugin used globally. https://wordpress.org/plugins/wordpress-seo/ . I use free ones and premium one as well. For a beginner, the free one should do. If you need you can upgrade.
Cache : It is very common practice to have a cache involved to avoid load on the server for all the static pages. W3 Total Cache is the most popular one and I have it across many sites. https://wordpress.org/plugins/w3-total-cache/ It works great and free.
Suite of Social Media, Follow, Comments, etc – JetPack : You will need a suite of services for email, follow blog, comments management emails, etc. Jetpack is considered slightly bloated, but it is good one to have. I have it on all my sites. It is by wordpress.com developers the core team. https://wordpress.org/plugins/jetpack/