We wish to go from Shanghai international to 839 Renmin Road Huangpu.

No, one cab in the city can only take 4 passengers. And I am afraid that one cab doesn't have enough space to put your luggage. Thus you are suggested to take two cabs.

The maglev is easy to catch from Pudong International airport (follow signs from the terminal). Show boarding pass as you will get cheaper fare. Luggage will be x-rayed for the Maglev (actually even for the metro line it is x-rayed). Catch a quick fast ride with no regrets as by road it takes over an hour (traffic is a nightmare). After getting off Maglev , go downstairs (elevated platform ) and the metro building is right there, you will need to buy metro tickets (hit the English button and you will need to have local currency (plenty of youtube videos showing how to buy ticket ) (western credit cards work nowhere except big hotels) . Metro line 2 to Nanjing East Road (about 15 minutes) station - hopefully you are not staying too far away.