the four living creatures

These are the four creatures mentioned in Revelation 4:6-8.

they fell on their faces

They lay down facing the ground. See how you translated a similar expression in Revelation 4:10.

"Our God is worthy of all praise, glory, wisdom, thanks, honor, power and strength"

The verb "give" can be used to show how praise, glory, and honor, are to be "to" God. AT: "We must give praise, glory, thanks, and honor to our God"

These two words mean basically the same thing and emphasize that the praise will never end.