It might depend on what the file formats is of the things you want to have in Archicad
Just copy and paste will work for most 2d things, there are are ways to import some things in 3d. If you can give a specific example of what you want to bring into Archicad I am sure you will get some answers for how to do what you need to do. In the case of importing an image file, Archicad has what is called the Figure Tool you can use for that. or you can just copy and paste image files as well if you want. https://www.youtube.com/watch?v=Gd2QStYNPho
this is a list of file types you can open with Archicad
If you are to import 3D objects in .GSM format, you can import that object via the object library. In the object library dialogue box, there is a small button located at the bottom of the screen where it allows you to call out the object library manager to import the LCF files or just select import to bring in GSM files.
Usually I like to just drag the actual files into Archicad plan view and it knows what to do automatically and it's much quicker, but this drag and drop method works best with GSM files.
JPEG images can be imported with the same method or you could use the Figure tool.