What should be one of my first purchases for my new career..?

Heels are your first purchase. Minimum height is 3 inches- anything shorter and your gut will stick out and your legs will look like tree trunks.

Look for a shoe with a plastic one-piece sole and heel. Shoes with the leather and wood heels are much more elegant but after the second night of dancing on them the heels tend to flex too much and put a lot of stress on your knees and back.