The words "back to square one" do not form a sentence, but rather a phrase. It is an idiom that means "we must start over completely". Think about a board game where the goal is to get from START (square one) to FINISH (square 30, let's say). Somewhere in the game, your game piece lands on a square that says "Go back to START". This is not good! You will have to "go back to square one". You will have to start over entirely. The second sentence is unclear as you've written it, so I'm not sure how to help you without further clarification. Do you mean "I think we've caught someone's attention?" To "catch someone's attention" means to do something which causes the person to notice you or look at you. "People catch a taxi driver's attention by waving their hands near the road or by whistling loudly." At a club, you may see a girl smiling and looking over at your friend. You may smile back at the girl, lean over to your friend and say: "It looks like we've caught someone's attention." You "caught her attention" by being so handsome, well-dressed and strong.