Tales of the Teenage Mutant Ninja Turtles was released as a Paramount+ exclusive. All 12 episodes. It's unclear yet if it will ever see a release on Nickelodeon.
As for my thoughts on the series, I've been tweeting about my low expectations in the lead up to the series, and it's pretty much what I thought it would be: not good.
It seems extremely low budget, and the choppy animation makes it very hard to watch.
MNTC summed up my thoughts pretty well in his review of the first episode: