Interview/school advise

Well, let me start of saying this has been a rollorcoaster ride. To even get to the interview I had to take a personality test and a program/typing test. Passed both with competative results. Then had my 1st interview which went well. I then had to take a language (spanish) proficiency test after the 1st interview. They call me back for my 2nd interview with a panal of 3 ppl. Well, since they took almost 2 months to call me back after the language proficiency test I started thinking about other options and signed up for a health science program at my local community college. Classes start August 29th. That's not the issue though. The issue is that before I start this program I have to get a background check, fingerprinting, and drug screening all before August 12th. My orientation for this program is July 29th and I was told to bring a checkbook because we would be purchasing uniforms that day. Hopefully these uniforms are refundable because if I end up getting this position I will end up having to return them or I would have wasted $100-$150. How can I let the company know that I have to hear back from them at least a week after the interview or I will be beginning this program I've signed up for? Should I just ask them during the interview about how long it will take for them to let me know whether I got the job or not?