And please make sure that before you sign a contract to purchase you have taken legal advice as to your intended use of the property, because it would be a waste of money if you were locked in to purchasing the property and then you found out that you could not carry out your intended use of the land, any good Solicitor will advise you as to what is called a special condition in the purchase contract that would go something like "this contract is in every respect dependent upon the purchaser obtaining all permits and/or authorities to operate/carry out upon the subject land the activity of motorcycle riding on a commercial and or competitive basis (and more related conditions)", and the specific words would be worked out by your Solicitor after taking your instructions about intended use and current zoning and planning position/requirements, and it is not an easy area of the law.
Please do not try and cut corners on good legal advice because even where the land you are buying is already being used for the purpose you want there can be difficulties so you need to make absolutely certain that you have the correct authorities/permission from the local Shire/Council and the EPA and any other departments that are involved, and that can even include the necessity to obtain consent from neighbouring landowners, regrettably the process can be quite involved and as said it is better to get good advice and make sure before you sign on the dotted line.
Remember, there are plenty of good conveyancers out there and they do a good job but they are not qualified to provide you with legal advice about planning and use of land matters and in this matter that would perhaps be the most important factor, and similarly there are plenty of solicitors out there who do a bit of conveyancing and a bit of family law and a bit of criminal law but they are not experienced in planning matters and although they might have a go at what you want to do they would perhaps not be as good as a Law Institute of Victoria accredited Property Law Specialist.