Next Steps (*such* a Newbie, I know...)

Thank you to all who helped me get started with choosing a wallet/client etc...

I generally consider myself relatively intelligent, but I don't feel so smart right now... even after spending ALL of last week watching videos, reading and getting myself mentally prepped to begin this venture.

So two people sent me small fractions over the weekend to get started...

I see them in my Blockchain wallet...

I went to the import/export tab and clicked on "import using paper wallet" and up popped a printable sheet with two QR codes, my addy and what I assume is the private key beneath the addy.. along with a mnemonic that is different than the original one I was given when I set up the wallet...

Questions:

1. What if I hadn't printed this sheet? Like, if I were out of printer ink or something... would I have lost access to the key associated with this address forever?

2. What would scan these QR codes, and when would I ever scan them (assuming my intent is to save BTC, not spend anytime soon...)

3. Is scanning just an alternative way to access the key/could the key be used without the scan?

4. Am I correct that the tiny series of numbers/letters etc beneath my BTC address is the key?

5. What is with the two-step verification? Is that necessary when I'm not spending? At what point is that relevant?

6. I'd like to choose a seller on localbitcoins w/high feedback, etc to buy a small amount of BTC from today. I know that'll mean going to a bank, etc - I've been reading through the different sellers' requirements, etc... but am I ready for this step, or would I be risking losing $ because of the fact that I'm not really understanding the whole "key" process/paper wallets, etc?

7. So my private key is sitting online in Blockchain, essentially, because it came from my wallet... right? So... oh, forget it... I'm just SOOOOO confused.

Thanks in advanced to any and all who can help me start getting the hang of this!