GST questing for Tour Operator

I run a tour operator business dealing with hotel and car vendor directly and tour package offered to customer. Plz help me how much GST need to be charged from customer. What will be my input if in case I have purchased a hotel room at Rs10000/- inlucding hotel GST of 18% and carhire with total cost of Rs.15000/- with GST from supplier. The final package offered to customer is Rs27000/- keeping Rs.2000/- as profit.

Secondly, I have few car vendor who are not registered under GST and they offer the car rate without GST. So in this case how do I need to show on the GST return and how do I show on the bill.

Thirdly, I also purchase readymade packages from other vendor who provides package inluding GST and I add the profit and offer to customer. So in this case how much GST do I need to pay. eg. Rs.30000/- package offered by vendor plus 5% GST of Rs.1500 - Total Purchase cost Rs.31500/- Now I want to keep Rs.1500 as profit and Rs34000/-is the selling cost. Do I again need to pay 5% on Rs34000/- or do I need to pay GST on Difference amt only as GST on Rs.30000/- is already paid.