Basics
Accessing Threads
Using threads
By default, your feed filters out some content
Under Settings -> Privacy -> Hidden words, "Hide replies that contain offensive words, phrases, or emoji" is selected by default.
You can toggle that off, if you wish, and/or select your own custom words and phrases you'd prefer not to see.
Each post can contain a maximum of 500 characters
Remember that Threads and Instagram are tied at the hip... at least for now!
If you delete your Threads account, your IG account will go poof! (suggested: deactivate vs. delete, which will only affect your Threads account)
Anyone you mute or restrict on Threads will also be muted or restricted on your IG account!
Understand the difference between Hide, Mute, Block, and Restrict
Hide just hides that individual post, so you won't see it (or replies to it) in your feed.
Mute will stop you from seeing a particular person's posts and replies, but they won't know you muted them.
Block is a bit more complicated / powerful
Per official Threads documentation:
They won’t be able to see anything you post on Threads
Their likes will be removed from your posts. Unblocking someone won't restore their previous likes.
They won’t be able to see your replies or any content you repost.
They won't be able to mention your username or tag you, even if you change your username.
Note that the person you've blocked won't be notified that you blocked them, but they may be able to figure it out.
Restrict will block notifications about that person including if they like, reply to, repost or quote your content. This is independent of whether or not you follow that person (e.g., you could conceivably hate-follow someone but block any of their replies... but why? :o)
Don't post nekkid pics
Just like with Instagram, nudity / porn / etc. is against Meta's terms of service and might get your account banned :o