Welcome to Eorzea!

That's normal, SE always puts up the patch download for players before the servers come back online. It's to balance out the patch so everyone isn't trying to download the patch all at once.

As for maintenence, SE often finishes maintenence earlier than they expect to (very rarely has it gone on longer than expected, I think it happened once in the entire six-year history of this game), so they'll usually post a message informing players about that beforehand. Just keep checking the Lodestone or refreshing the page on the launcher and the world status should go from red to green eventually.