When my shop moved from AIX to Linux we just install Oracle on Linux and patched it to the same level as the AIX. We created users, tablespaces, job etc in advance and then just used import/export to move the needed schema's. Data Pump make this much easier.
Do a schema(s) compare and switch when ready. But in any event I don't believe Data Guard can help you. You mostly have a migrate issue.
Please consider closing your question when complete.