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. Â Whichever acid you use to lower pH will also lower alkalinity. Â After you get the pH where you want it, you can start building TA with baking soda. Â 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. Â 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. Â At high pH, calcium tends to precipitate out of solution, forming scale.