I have generated bindings for Google Ads for my project. I can answer one of your questions that the generated code is all you need. Check the original documentation of the third party library to find the method you want. The generated code will have a similarly named method. Trial and error and code completion will help you here.
For example, the code to display an interstitial ad of google ads. This is the code in Obj C:
self.interstitial = [[DFPInterstitial alloc] initWithAdUnitID:@"/6499/example/interstitial"];
[self.interstitial loadRequest:[DFPRequest request]];
Using the moe generated bindings, it will be like this in Java:
dfpInterstitial = DFPInterstitial.alloc().initWithAdUnitID("/6499/example/interstitial");
DFPRequest dfpRequest = DFPRequest.request();
This was the thread I created when I had trouble with the generate binding option. If it helps.