As above what training would you recommend carrying out ASAP to a newly passed cat C driver? Straight into C+E? HIAB? ADR? Etc…
Thanks 
What’s your budget?
There’s a massive difference between ADR or Hiab (about £350-£450 depending on a range of factors) and C+E which will be comfortably over £1000.
Practically speaking, Hiab and C+E both require you to have experience to get work, where as that limitation is less of an issue with ADR.
Neither. Get a job asap and get that experience.
ADR has the advantage especially on agency of more work as it seems there’s a genuine shortage of that (although it would help if it paid more than non ADR).
Also there’s less chance of a major or expensive screwup as theres really not much more for you to do beyond remembering the paperwork and some basic rules. Almost everything else in the case of basic ADR stuff is taken care of by the office.
HIAB has more chance of problems such as people wanting stuff in awkward places or building sites hazards which can be enough of a pain at the best of times. Learning to drive a class C can be stressful enough initially without added stress.
Class 1, some say its a good idea and it does take you out of the bigger pool of drivers. But it does also take a lot more learning and as mentioned it is much more expensive. Honestly not sure if its financially worth it as the pay rate is often very similar.
I’d maybe do class 2 even without other stuff then run that for a year and see if you like it, as long as you can get a job which is the harder part.
As above. Best to get in and around the industry and then you’ll get a better idea of what might appeal and where there’s demand.
It’s normally said that holding a Class One will enhance your prospects of work as it opens up more opportunities. But the investment is relatively big and may not be necessary.
I wouldn’t recommend doing loads of qualifications on the off chance you might find one of them handy. Better to do them as and when the need arises.
Whatever you choose to do, all the best with it, Pete S 
Plenty to think about thanks lads! I’ll try get the experience first then I think.