Should I join the USCF or FIDE to get a rating?

Depends on your goals. USCF is US based only. FIDE is international.

I don't follow you here. I have a USCF rating, I have never had a FIDE rating. To get a USCF rating you just have to join the USCF and play USCF rated games.

I would advise yes do it, not just for the rating and to truly judge your chess aptitude, but to experience over the board competition because there is nothing like it. To actually see and feel a chess set, to make eye contact with your opponent, to analyze your move with a chess clock ticking and possibly have several people looking and judging your moves, to actually shake an opponent's hand after feeling the jubilation of a hard fought win or the pain of a difficult loss. Truly, that experience is worth the effort to get an OTB rating.

USCF

nah if you are an american, USCF first ...

Why don't you start from a more reasonable angle? Find an OTB tournament that is convenient for you, and find out what do you need to play.

To get a USCF rating you must play in USCF tournaments. When you sign up to play in a USCF tournament you will be required to join the USCF. Some American tournaments are also FIDE rated but don't require FIDE membership to play or get a FIDE rating. This is done to accommodate any foreign players or FIDE members that are playing in those USCF events.

OP--you must join USCF first before you can obtain a FIDE ID number.

In order to get a FIDE rating, you must first join a National Chess Federation (via a chess club membership). Your FIDE id will be provided via the National Federation.

But alternatively, you can get a FIDE id via a subscription to the FIDE Arena. At least this was the case a few years ago, and I guess it still applies, although FIDE does not really care about the platform anymore.

Ok this is easier to understand now thank you guys!

Hahaha. No. That's not how it works. Tell em the truth. The truth is u go to a u.s. tournament & when u go into the playing room/area u announce very loudly that ur in ur first tournament & ur there to open a can of woopazz on anyone u play, so they better get use to it. And every time u put ur opponent in check u have to have to say check loud enough for everybody to hear. They'll understand because it's ur first tournament. If u do those things, & u have to, they're mandatory, they'll automatically put u in fide along with uscf.

FIDE's members are countries, not people (well, there are some exceptions where a person has no country or the home country refuses to let them join their national organization).

That country will create a FIDE ID when the person plays in a FIDE rated event. Since you have a US flag I am guessing you are a US citizen (the chess.com flag doesn't have to match a person's actual country but it usually does) and thus you would have to first join US Chess. There is a growing number of US tournaments that have some or all of the sections being FIDE rated and every US Chess player who plays in a FIDE rated section needs to have US Chess staff create their FIDE ID number if they haven't already had one created (even if it is the player's first time playing in a FIDE tournament a FIDE ID would also have been previously created if the player was already a licensed arbiter in FIDE).

FIDE keeps lowering the rating level for a publishable FIDE rating.

The rating floor was initially 2200, but was lowered to 2000, and later to 1800, then 1600, 1400, 1200 and now finally 1000.

7.12 (in the FIDE rating regulations)
The following data will be published concerning each player whose rating is
at least 1000 as of the current list:
FIDE title, Federation, Current Rating, ID Number, Number of games rated
in the rating period, Year of Birth, Gender and the current value of K for the player

AND

7.14
A rating for a player new to the list shall be published
when it is based on 5 games against rated opponents. This need not be met in one tournament.
Results from other tournaments played within consecutive rating periods
of not more than 26 months are pooled to obtain the initial rating.
The rating must be at least 1000.

Hard to imagine no one has given clear advice without contradiction.

I want to join your club and start playing live tournaments. I am a member of no federation. Do you advise joining USCF before entering a tournament? Am I allowed to play without membership? Does it make sense for an unrated player to join FIDE as well as USCF, assuming it's permitted, which is not clear given contradictory comments here.

Impossible to answer those, as there are too many unknown factors.

A more reasonable approach would be to pick a tournament near you, look at their website, and see what membership is needed (if any).

Or, if you live in a city, join a local chess club - they will probably organize tournaments of their own.

The OP is probably not from Norway. It was him who said USCF in the title, so probably American.

People use all kinds of flags for all kinds of reasons.

This was posted last year so the member may have had a different flag on the account and they specifically asked about US Chess as well as FIDE