Hello there, the anime has already ended. There's no s2 either s3, the Steins Gate 0 series is just an alternate series.

Steins Gate's anime is based on the VN, and the original VN is ended. There's some spinoff too, but most of them is noncanon.

The true ending is that of the movie, and the OVAs act as a bridge between the anime and the movie. :v

The movie and OVA are not canon, as they conflict with the official Steins;Gate epilogue story (sadly hasn't been translated as of yet).

Every time someone asks this about adaptations completely ignorant of the fact that they're adaptations I die a little inside.

Yea, i'm also pretty sure its over the anime debuted on 2011, and now its 2020. Also what does (Not canon and canon) mean?

Not canon essentially means the events did not actually happen in the series' universe. The movie didn't, or even *can't* happen in Steins;Gate's universe, as it breaks established rules about how worldlines work.