In addition to @SethCNC’s excellent advice take a look here https://inventables.zendesk.com/hc/en-us/articles/360012849233-Carving-Bits-101-Bit-Basics
also: Color-coded pdf poster of all the bit sizes? - #3 by LeeWyatt
and check out the inventables YouTube channel - there’s various videos on bits and their use https://www.youtube.com/@inventables