Page 69 - Homeworld skills indicates that "A character receives one specified skill for each trade classification or Remark from the homeworld. For example, a character from an AG Agricultural world automatically receives Animals-1."
So homeworld skills are one for each remark or classification that has an associated skill (not all do).
As for 0 level skills there are three types of those. First one is default skills page 143 are zero level skills everyone gets and there is a list of 12 default skills on page 142. Second one is Hobby also page 143 which is one skill characters choose at the end of character creation (so long as they did not get a hobby from character creation) that is for that character a zero level skill. Finally there are the skills with knowledge contained within them the first two time the skill is received the character gets a knowledge and has skill-0 in that skill, the third time they get the skill they get skill-1 which is from page 144.
So homeworld skills are one for each remark or classification that has an associated skill (not all do).
As for 0 level skills there are three types of those. First one is default skills page 143 are zero level skills everyone gets and there is a list of 12 default skills on page 142. Second one is Hobby also page 143 which is one skill characters choose at the end of character creation (so long as they did not get a hobby from character creation) that is for that character a zero level skill. Finally there are the skills with knowledge contained within them the first two time the skill is received the character gets a knowledge and has skill-0 in that skill, the third time they get the skill they get skill-1 which is from page 144.