Auto invoice generate number with Save as PDF Macro with

Hello Guys,

In my school project I have to create an invoice on excel which can generate an invoice number (+1 to previous one) when saved, the save as function should be a PDF format. so we can email it.
Once we have created the PDF we need to go to main screen and clear the fields. we should be able to repeat the above so the invoice numbers keep on rolling.

So if we break it down we need 3 macros:

1) Auto generate invoice number (Macro called Finalise)
2) Save as PDF Macro, file name should be the new generated auto invoice number. (Macro called Generate)
3) Save the current EXCEL file (so the invoice number is maintained) and return to the homepage and clear the cells with data so we can start a new invoice. (Macro called Return)

Homepage tab name: Basic Info
Homepage cells to clear: J4, Q4, J6, Q6, J8, Q8, J10, Q10, J12, Q12, J14, Q14

Invoice AutoNumber field where invoice number is required: DTA!G19 (sheet tab: DTA, Cell number: G19)
Invoice Number format: "QLHR-J18-01" (the value in BasicInfo!J18)

Please let me know if the above is possible,

Thanks in advance guys

Tai