You need to apply for a Tourist Visa (L visa) to Mainland China and a visit visa to Hong Kong, the requirements for L visa of Mainland China are:
1.A valid passport as well as a copy of its information page: Your valid passport must have at least six (6) months of remaining validity and at least one blank visa page in it.
2.Application form: One completed Visa Application Form.
3.Photo: one recent photo of 2x2 square inch (black & white or color is acceptable) glued or stapled on the application form.
4. round-trip flight tickets

The required documents for Hong Kong visit visa application:
The applicant's recent photograph (affixed on page 1 of the application form ID 1003A)

Photocopy of the applicant's travel document containing personal particulars, date of issue, date of expiry and/or details of any re-entry visa held (if applicable)

Photocopy of proof of the applicant's financial standing, e.g. bank statements, savings accounts passbooks, tax receipts, etc. and proof of employment (if any), e.g. company leave letter, salary slips, etc.

Photocopy of proof of transportation arrangement, e.g. flight itinerary

Photocopy of proof of the proposed leisure visit to Hong Kong, e.g. receipt of joining a package tour to Hong Kong, itinerary, etc. (for leisure visit only)

You can apply for China visa and Hong Kong visa at the same time, please submit application to Visa Office of the Embassy or Consulate -General which holds consular jurisdiction over the state where you reside;

For the Hong Kong Visa itinerary, do i need to consist of my whole china trip itinerary or just my visit in hong kong?

Thank you.

You visit in Hong Kong is required.