UK Maintenance in a commercial building/quals?

[Terrytonic]

Hi all, I’ve just joined the forum in the hope that I can clarify the route I should take. I was self employed for many years doing domestic work. In this time I worked with electricians and gained a fair bit of knowledge and experience, I’ve also worked with gas engineers and helped with fault finding on s and y plan heating systems. So not quite a novice. I am employed now and have been for sometime. I do maintenance for 3 venues across the northwest and the company is willing to get me qualified to work on the electrical side of things. I would like to know which route is best for someone like me. Looked online, too many courses that look like a rip off and how many c&g numbers???? Which do I actually need?
T.i.a

Terry