Is there an online PC game where you're in the old west, an choose your profession (maybe), and has many continuities, like Ultima Online?

Found one: https://www.playwwo.com/

what about the new New World?:O

The only one I can think of is Red Dead Online. It has some issues but it is quite fun if you get into the roleplaying spirit.

So Red Dead Online is Red Dead Redemption II, while Red Dead Redemption I isn't an online game?

It's the map of Red Dead Redemption 2, but you play as a custom character in a map shared with other players (though not MMO style, it's limited to a smaller number in individual instances), you can explore/free roam or do missions either solo or with other players. It's fun, not as good as the single player RDR2 but it's still quite enjoyable when you really delve into it.

Both games have online and offline content, use the same map for both modes, and RDR2 has the first game's map included with its own. RDR1 is also less laborious with the animations, so you can choose whichever is more your speed; but RDR1 is also exclusive to PS3 and Xbox 360.

Cool. So is Red Dead Redemption I with zombies, and the other stuff isn't?

What about this one? Does it fit the bill?

https://www.innogames.com/games/the-west/

RDR1's third and final mode is a zombie-themed offline expansion and RDR2, as far as I know, has no expansions for now.

If you mean both Red Deads with "zombie optional", that sounds about right. It seems rare for MMOs to have M-rated content to begin with.

Yeah, in the non-zombie games, the regular games, no extreme blood or anything, like when people get shot. I ask because I'm looking for some kind of online Wild West game for a family member of mine who grew up with the old westerns from back in the day, and when people got shot, they just fell over and died, no extreme blood shooting out from gun shots, or things like that or worse.

There is Desperados and Call of Juarez.

Edit:
Yeah I wasn't paying attention to the details of the inquiry. My bad.

You mean "Desperados: Wanted Dead or Alive"? And the others talked about above do have a lot of blood and stuff?