No-you do not have to be 18 to call and talk to an attorney.
You do have to be 18 to enter into a valid contract and you could not have another
person's power of attorney until you were at least 18(depends on State law).
The answer given does not imply that an attorney-client relationship has been established and your best course of action is to have legal representation in this matter.
You can consult with an attorney before you are 18. Contracts for minor's are voidable so retaining an attorney may be a challenge. Hopefully the lawyer you consult with will know what lines cannot be crossed with parental consent and other issues, consistent with attorney client privilege.
The above is general legal and business analysis. It is not "legal advise" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.