Most recommendations say to get Alkalinity in range first, but I feel that when starting at a high pH, you have to deal with that before moving on to balance the water. Whichever acid you use to lower pH will also lower alkalinity. After you get the pH where you want it, you can start building TA with baking soda. That will also drag pH up slightly, so it becomes a balancing act, as you find the right ratio of acid/soda to fine tune the readings. I personally don't worry about TA unless the pH is unstable.
IMO, you shouldn't add any calcium to the water until you get the pH balanced. At high pH, calcium tends to precipitate out of solution, forming scale.