Zwift newbie help

Any help will be great.

  1. I use the whoo kicr, do I need to do a spin down 10 min into my warm up, I am using zwift for racing and done my FTP test, got 225.

  2. Does all races (cat A,B,C,D) be at the starting line of a race and if so how do you know which races are in your CAT, so I am not trying to follow a CAT A.

  3. How do u know you have a power up in a race and how do you use it.

  4. I am using an iPad for zwift, and my samsung for the company app, but the company app is not in sync with the iPad, both is on the same network.

Sorry for all the questions.