Is there a way if I create a cluster of objects (layers) on one page to copy those and paste them into another document?
There are probably several methods to do that, but here is one that is fairly easy.
Below is a screenshot composite showing two untitled documents. The first (Untitled 1)has a red background layer with 3 shape layers, a text layer and another blank layer. The second (Untitled 2) has a plain green background layer.
Select the layers that you want to copy. They do not need to be contguous. I have selected the text layer and one of the shape layers in Untitled 1.
Right-click on one of the selected layers and choose Duplicate layers. This brings up a Duplicate Layers dialog. (You can also select Duplicate Layers from the Layers menu.)
All files open in the Editor will be listed in the dropdown menu of the dialog. Select the one that you want to copy the layers into and click OK. (If you only have one layer selected to duplicate, you can also rename the layer in the dialog.)
The selected layers will be pasted into your chosen open file - here Untitled 2.