Venezuelan Passport Holder

Marian, you are definitely eligible for 24 hour via free transit and you don't need any kind of visa.

You will print out your flight tickets and have those printouts with you. Also, you will declare at check-in in Frankfurt that you will travel to Melbourne via Shanghai using 24 hour visa free transit. After a short inspection of your tickets, you will be allowed to board the plane.

Upon your arrival, you will clear the usual formalities and will continue to wait for your flight to Melbourne. Quite simple.

Of course, you are allowed to apply for a temporary entry permit if you would like to be allowed to exit the airport and shortly to explore the city and this application is completely free of charge. Anyway, you never know what will be a decision of immigration authorities. They may, but also may not allow you a permit. In any case, you don't lose anything.

Keep in mind that Venezuelan passports' extension stickers ("prorroga") are not accepted by Chinese immigration. Your passport itself needs to have a 3-month remaining validity for you to transit Mainland China.