You can run the carbon and filter pad block. You also can add gfo or anything else later down the line
The sponge thing yep that goes on the bottom. You will have to rinse it in used tank water when you do water changes to keep out the debris that will raise your nitrates. GFO= granular ferric oxide. It is used to soak up phosphates which cause and fuel algae. You can run some chemipure elite in your AC filter basket. It's carbon and gfo.