It's "there" not "thier" - seriously, you want to be taken seriously, spellcheck - or more English classes. Not pointing it out to be an ass, just saying.
Anyway, on to the issue at hand, if you head on over to;
And punch in your qualifications (schooling, element preferred etc) it will match you up with suitable trades. To see if a trade is open to "off the street" applicants such as yourself, you want to look at the trade summary and find "Qualification requirements". For instance the Int Op reqs are;
"Entry Plans: The Intelligence Operator occupation is usually available through Occupation Transfer....Other applicants to be considered are:
Civilian personnel who have formerly served in the CF
Component Transfer applicants who are re-enrolling or transferring from the Reserve "
On the other hand, my trade is completely open to walk-in applicants, as are most trades in the Forces. Just make sure to pick something you find interesting, and once you run through the application process things will work themselves out. The aptitude test will most likely be the deciding factor on whether or not you can pursue a trade.