Yup ... recommended would be 6189 Lvl2 (NVQ2) for basic pipe skills in soldering and laying out etc, really quite essential for good gas work. NVQ3 for advanced work in design and theory in hot and cold water systems and central heating design, again recommended if that is the proposed career direction. The NVQ's also give critical all round on site experience.
Then it's onto the course for the Gas foundation cert, needed before a portfolio is allowed to be created, a Class 1 course with a 6189 NVQ3 or class 2/3 without an NVQ. There's less work in the class 1 foundation course as course material is covered with the Level 3 work & then as Dan mentions, there's around 150 hours of practical onsite work creating a portfolio with a GSR engineer out in the wild, prior to being allowed to sit the ACS final exams. Once all that's done then it's register with Gas Safe.