How do I block "suggested for you" posts on Facebook?

I hope this is the right place to post.

I need to use Facebook for work and it's an account I made that originally I wasn't going to add anyone. But ended up having coworkers adding me so I post once in awhile, mostly work related to seem social so I can move up and around the company. I can just get on whenever I need something work related but I've realized, I should "network" by looking at others posts and liking it and whatnot. But I'm so annoyed by all these spam, and the fact that the news feed aren't in order. Ugh.

I've got ad blocker. I don't have the fb app. I use the website on my Firefox mobile browser.

Is there any way to block all posts that isn't from people I know?

Update: Thanks for the suggestion of Friendly app. It works! Hopefully I get push notifications too so I don't keep missing opportunities on group postings. No, I cannot stop using fb when all work stuff are in multiple groups that I need to make my life simpler. And no, I don't use a computer at work or have a work phone.