Can you be charged? Off the top of my head, I cannot think of any crime with which you may be charged for attempting to purchase drugs. Maybe attempted possession? But, that seems like a big stretch. Of couse, if your case is in front of an overzealous prosecutor, there is always a chance you will be charged.
Will you be charged? That is a different question. Given the tenuous and nebulous nature of the potential charges, as well as the fact you have no previous drug history, probably not. Again, an overzealous prosecutor may try, though.
If you did anything other than attempt to purchase drugs over a phone or there are more facts to this scenario, this analysis may change. If there is more than meets the eye here, I suggest you consult directly with a local, experienced criminal defense attorney. The more you post online, the less confidential your case becomes. Also, anything posted online may be used against you in court.
There are a few things that will make it either more or less likely that you will be charged with a crime.
Were you arrested or taken into custody by the police? If so, that could mean they have information about the event that we do not, and that may make it more likely that they are planning on taking information to the DA to have you charged with a crime.
Do you believe that the police have evidence that you purchased drugs in the past, or were involved in the drug trade? For example, were they monitoring the phone call, or were you attempting to purchase drugs from an informant? If so, that could also make it more likely that you would be charged with a crime.
If you are not sure if you are being charged, you may be able to call the District Attorney's office and ask if they have any charges filed against you. You are in Juneau County and can contact the DA there.
Remember, that being charged with a crime is not the same as being found guilty of a crime. A good criminal defense attorney may be able to work out a deal to reduce charges or at least minimize your time on probation or in jail, depending on the facts surrounding your case. Every circumstance is different, and it's impossible for any of us here to know for certain without knowing more about what exactly happened.
Best of luck to you in your case.