ABN entitlement decision - Not entitled
On the basis of the information you have provided it appears that you are not currently entitled to be registered for an ABN.
Basis for decision
As you have not demonstrated that you have commenced operating an enterprise, or have indicated that your business activities do not constitute an enterprise, you are not entitled to be registered for an ABN.
It's ok to apply ABN before you start a business or contract work. I think there is a test on ATO website to determine if you are an employee or a contractor. You can have a look.
The following table outlines the differences between employees and contractors based on the six factors which need to be considered when determining whether a worker is an employee or contractor.