One-year-old decks. How to treat?

I bought a house in December. There are two decks that had been installed the previous May (one year ago). The previous owners did nothing to the decks and told me that they should be stained this June -- so 13 months after installation.

There are already splinters and splits so it seems like something should be done soon.

Image attached that shows writing on deck indicating the kind of wood, I believe.

What should be done now to fix the damage that's been done and to protect it.

Also, is it OK to sand off the writing on the deck? It's in a very visible spot.

Thank you for your assistance.