As Pima and others are saying, this is NOT rocket science. You do not need a consultant. You don't need practice mock interviews. I will say that for a civilian university; especially the highly coveted and competitive ones; a consultant can be a good idea. That's because there's so many facets to how to get accepted.
But for the academy; you as the applicant obviously has to take care of your grades, physical fitness, getting into extra curricular activities, sports, volunteering, etc.... That's your job. No one can help you with that.
Next. When you do your essays and such for the academy and your MOC nominations, have people who are smarter than you, proof read it. You'd be so surprised to know how many applications and essays I've read with basic spelling and grammar errors. The content/subject matter is already chosen for you. You don't need someone to tell you what to write about. But someone to proof read for you would be great.
Then; as far as interviews go, there's only 2. Your MOC and your ALO/BGO/MALO. Chances are, the ALO/BGO/MALO is going to be a bit "Less formal". At least for many it is. But as for practicing for this, start by assessing your communication skills. Ask your teachers what they think of your communications skills. Do you use the word "LIKE" every 3 words??? Do you say "Ummmm" every 4 words??? If you give a report in class or need to give any type of speech, do you jitter around??? Are your hands flapping around? Are you nervous? etc.... Once you have assessed what your strengths and weaknesses are, simply make it a point to correct them. Make a bet with your younger brother/sister that every time you say "Like" or "um", you'll give them a dollar.
Bottom line: There isn't 1 thing in the academy application process, that you need to "Hire" a consultant or professional for. It's a waste of money. Again; I will concede that for civilian schools, where there's many more angles to come at it from, a professional could help. But you've already taken the best step you could. You came to this forum. How many of the 12,000+ applicants to the air force academy do you think visit this forum??? There are 17,266 members in this forum. MANY of them, once they get to the academy or graduate; or are parents of such; no longer visit here. You can't turn lead into gold. All you can do, is be the best that you are capable of. You don't need a paid professional consultant to do that.