Yeah, they do teach obtaining clearance.
To be a bit more clear, my question is: when you depart from a CTAF that is under the steps and you are climbing out into class C and you really only have a matter of minutes before you enter into class C because the airfield is high. (Eg YRID which is 1150ft elevation and class C is 2000ft, so only 850 ft above you), is it possible to get airways clearance before you take-off whilst on the ground at the CTAF.
If you train at a class D or a CTAF in the middle of class G then most new PPL holders will never have had to do this.