I know its a little late, but for someone who's historically had a lot to say on topics like this - I just didn't feel like it was the right time. I'm still not sure, but there's that little feeling that I ought to, so here we are.
Over the past 12 years (holy shirt... where has the time gone), I've had the pleasure of seeing the work of some great CMs, and fortunately, never actually come across a terrible one.
I'll start with the hard/heavy stuff first - back in the day, SE was nothing but Q&A. The company was small and they breathed and slept and ate the stuff we do here. Over time, that changed - and the focus went elsewhere. While things got better - you lot are the folks who're going to end up needing to be the subject matter experts and voice of the parts of the community we use. While at the time of this question, a hiring was kinda closed off to a lot of folks in the community - you either are, or have colleagues with some degree of network experience, or probably have the tools on hand to tap into the community if you need to.
While the platform is 'the same' - one finds quirks in many communities, certain personalities of interest good or bad and (dear god so much) gossip amongst mods. Some of this can be useful to know. If you are from outside the platform - its probably useful to learn about general quirks, and ask around/find stuff on meta, and both the SE blog and Jeff Atwood's blog about why stuff was done in the early days - I find this and this interesting reads. There's quite a few more things I find I refer to, given the context.
Back in the day - meta was a 'core' part of the community manager workflow. It was even part of the application process. While somewhat time consuming its an essential part of understanding a community. While main meta is more 'exciting', I learnt my skills on per a site meta first. While as a moderator, I do have somewhat more freedom - its an opportunity to turn a embarrassing or hostile situation into one where you're able to pull the community in the 'right' direction, or to realise mistakes were made and try to rectify the situation. Its going to take a while to learn, so don't stress it, and unless its something legendarily bad, chances are the community is going to have your back, or at least let you know where things went down.
The theory of moderation post on the blog talks about the role of moderators as
As a moderator, your actions now represent the community, so you will be held to a higher standard of behavior. You are an ambassador of trust, with the same sorts of rights that the official development team and community coordinators have.
As a community manager - your actions, or in some cases, lack of it represents the company. You're its voice - and the ambassadors of trust. You speak with the voice of the company to us, and to folks in the company for us. Sometimes you will be underappreciated (hopefully not by us!) and put in unenviable situations where difficult decisions need to be made. Sometimes even a Kobayashi Maru Scenario.
If anyone said it would be easy, they probably have a bridge to sell you. Whether its all worth it? Well - if you're a CM reading this, possibly, but that's a judgement for you to make.
Done right - your work will be remembered for.... well at least a decade, maybe more (Oi! Realistic expectations here!). You'll have challenges and sometimes do something so glorious you can't tell anyone. And least for the folks who're the heart of the community, the ones who're here, and working on making the site better, you're all needed and appreciated.