RE: I'm totally new to the Steemit Community and know pretty little!
Welcome man! I know it's a lot to absorb in the beginning but I promise it's not that bad 😆.
There are lots of resources for newcomers to learn about the platform, the do's and dont's and such. Personally, I like @minnowuniversity - lots of good information there! MSP (minnow support project) has lots of great stuff for new Steemians.
To answer your question though, Steem is sort of the default currency that the platform (and other platforms on the blockchain like DSound and Dtube) uses. Steem Power is like the power your account holds - it affects how much your upvotes are worth essentially. So you can think of Steem as like your liquid, movable Steem currency, where as SP is more of a long-term investment in your account in order to up your vote weight and influence. Once you 'power up' (converting Steem to SP) it takes time to take that investment back out - think of it like your checking and savings account, but your savings account also adds to your upvote value. It's important to get your SP up because its essentially your influence on the platform, so in the beginning I would recommend powering up whenever you can.
SBD (Steem Dollars) is a sort of an alt currency that was supposed to match one USD. As you can see, it's price has fluctuated and inflated past that by a good deal, so it's original purpose has kind of been lost. Nowadays, you will receive a good chunk of your author rewards in SBD. There isn't really an upside to holding SBD over Steem (aside from the ebb and flow of current market values) so at least personally, whenever I can get a good return on SBD to Steem I will convert it. Otherwise, I'll typically hold it until I can do so.
Hope that wasn't too off-the-mark! Welcome and have fun!
That was actually a better explanation than I've seen anywhere else. The benefit to loading up on SP besides having more influence on the upvotes is? What is an average SP holding?
Nice, glad to hear it! I mean, that's basically it lol, but it's a big one. There are a lot of little side effects that will come with having more SP though. For example, I've noticed as you get your SP up, you will notice a steeper gain in followers because they are looking for those higher upvotes. Great content aside, some individuals will follow for that reason alone. It also gives you more influence on who you would like to see succeed on the platform as well.
There isn't really an average for SP, as the range of size is pretty immense. For example, I hold around 2k right now, and I'm still considered pretty small. You might hear the term 'minnow', used to describe a user who is less than 5k SP (ballpark). 'Whales' on the other hand, are massive Steemit accounts, who can sometimes hold millions. Sometimes these big accounts are run by collectives, not necessarily individual bloggers.
But anyway, yeah it's essentially a power thing. The more influence you have, the more you can sort of pave your own success or the success of others, at your discretion. It's a slow burn but if you really want to stick around for the long term, I'd definitely recommend packing on that SP!