What courses you need will depend ultimately on what your employer is wanting you to do, but as Pete has already pointed out courses are only part of the equation, relevant experience is key as well.
Courses will allow you, to an extent, to demonstrate your competent enough to pass exams and complete practical tests.
At the very minimum, in my opinion, you should consider C+G 2382 which is the wiring regulations, 2393 (IIRC) which is building regulations for electricians (so you can understand how these apply to you) and potentially 2391 which is inspection and testing (you could potentially skip 2392 which is initial verification (covers single phase I+T on new works only IIRC).
I do quite a bit of work on a static mobile home park and for the most part it's just like domestic.