Never buy a "starter set", unless you want a bunch of bits that you'll never use.Each application will require different bits.
Having said that, here's what I'd get:
1/8" and 1/4" downcut spirals.
1/16" and 1/8" ballnose, or tapered ballnose.
60° and 90° V bits (high quality).
"O" flutes are for plastic and aluminum. (don't use the same bits for both)
Different materials may require specific bits for best cut quality.
There's no substitute for years of experience and trial and error when deciding which bits to use.