Should President Biden send the US Navy to the Crimean sea?  To stop Putin from invading more of eastern Ukraine as he is threatening...?

Yes he should, we need to remind Russia who the hell is in charge.

Er, Ukraine was threatening to invade Crimea. That is why Russia is taking defensive action.

Obama sent blankets in the last skirmish between the two.  Trump sent weapons to Ukraine.  Biden would send booklets about carbon and tell the Ukrainians to give up their sovereignty peacefully.

Personally, I don’t see Ukraine, as America’s business.

The Black Sea is Russia's domain not the USA's. Russia have a naval base in the Crimea, and there's nothing the USA can do about it.

Ukraine is culturally and linguistically similar to Russia. I see nothing wrong with Russia reclaiming Ukraine. The Soviet Union may have collapsed, but borders don't last forever. The Soviet Union was the main power in WWII. It's no surprise they would continue to be the main power in the region to this day. Whether Ukraine is part of Russia or not, doesn't really make much of a difference. Russia could annex Finland as well and it would have little impact on the U.S.