Accessing Tor "safely" is something over and above accessing the normal internet safely. Advice like "don't open PDFs" isn't very helpful. Nor is "don't use javascript" or "don't log into social media." Such inactions don't help you access anything safely, they help you not access things in the first place.

(1) Use a secure OS. Unless you are security guru, that should be some flavour of linux. A liveUSB of Tails is pretty idiot proof. It worked for Snowden.

(2) Don't run any web browser, tor or otherwise, under any sort of elevated privilege (ie not while admin).

(3) Understand how to verify a website's certificates. You can indeed log into social media safely via tor (ie your password won't be harvested by the exit node) if you know how to verify the website.

(4) Don't take anonymity casually. Understand why you are using Tor, what you are protecting, who your adversary is, and develop relevant procedures. Don't rely on easy checklists you find at Tor-for-Dummies.com.