I don't know which TEFL qualification you mean, but could I PLEASE ask you to make sure that you get a qualification from a recognised board? This is the only way you can ensure that your qualifications are respected and credible. There are a lot of people out there with an 'Intro to TEFL' qualification which is quite useless in the job market.
I have been in TEFL/TESOL for quite some time, and despair when I see people wasting their money on courses that have little value in the employment market.
Two well-respected qualifications are Trinity Cert TESOL and Cambridge CELTA, and both of these have mandatory supervised teaching. These are what we look for when recruiting teachers. Have a look at the following:
http://www.cambridgeesol.org
http://www.trinitycollege.co.uk
Good luck with whatever you decide.