What is "newbie" as an adverb?

Solution 1:

Noobishly/n00bishly is the most widely used adverbial form, I think.

If you talk that n00bishly about it, do you even know what it is?

can someone noobishly splain to me the O(1), O(N), O(N^2) and O(log N)?

After googling for various possible adverbifications and comparing hit counts, this seems by far the most common:

newbishly    2,390  
noobishly   14,300  
n00bishly   13,800  
newbily      4,670  (mostly not genuine adverbial usages)
noobily      2,600  (ditto)
n00bily        100  (ditto)

Google hit counts are, of course, not a terribly precise measurement; but in this case the results seem reasonably convincing.

The other relevant question is whether newbie, noob, n00b themselves get used as adverbs. This is of course much harder to search for; I’ve not been able to find any examples, and I can’t imagine any that would sound natural, but that doesn’t mean it doesn’t happen.

Solution 2:

If I wanted to use newbie in an adverb like manner I would go with:

he was running like a newbie

rather than creating some clumsy construction like newbily or newbishly, although I have heard the latter used.