The thing is, it’s not about the licence. You’ve passed the test, you can do it. So, newly qualified or experienced, all the same at the start of a job with a new firm or different type of job.
It’s about the job. What does it entail, how do I operate this piece of kit I haven’t seen before, what do I do if “This” happens, or “That” happens. How does the paperwork work. What’s this Hand Held Terminal thing?
A multitude of different things that have nothing to do with the actual driving bit.
This is the sort of stuff that would worry me, tbh, not the driving part.
My first job (Agency, 7.5t, yeah yeah, I know) I got stymied by a fold under tail lift. Was banging it on the floor wondering why it wasn’t folding out, didn’t realise I had to horse it out meself 
Ok, I found out later how it worked.
My first time driving a small lorry after 30 years layoff I was a bit lost. But it wasn’t the driving, it was the job.
Plumbers supply, from taps to shower bases, piece of ■■■■. 30 drops a day ffs.
What’s the plan, Boss?
Oh, so I just drive to these addresses, knock on the door, hand em a package, get em to sign, and that’s it?
Yeah, only it ain’t, is it 
.
Customer not in, no parking within half a mile, wrong part supplied, wrong customer phone number, can’t find part on the truck, loading crew wrongly numbered the package, customer not in but, on the phone, says “I’ll be there in 5 minutes” but they aren’t. You wait 15, what now? just ■■■■ off? what’s the procedure?
But that’s just multi drop.
A newly qualified driver should have no fears about going out on his own, doing the driving. It’s the job that’ll ■■■■ you up.