Ask HN: A Tale of 2 job opportunites

About me - coding for about a year and a half. I love it, but I know there's a ton left to learn. Mostly self-taught at this point.

I've gotten myself to a point where I'm on the cusp of moving into my first technical position. There are two opportunities on the table now (probably more if I shake the tree harder).

Opportunity 1: Employee #3 (and first tech hire) at eCommerce startup The site is powered by php and Magento (I have no experience with either). I'd be working with 2 remote developers who know the platform well, and could potentially bring on more remote devs/advisors. Good comp,equity and responsibility.

Opportunity 2: Employee #10 at well funded startup. More of a support role, but the team seems brilliant. Stack is mostly js from what I can tell. Not sure how much I would code day to day (at least to start) but I feel like I'd learn a lot just through osmosis. Don't know about comp yet ( I still have to interview for this one)

So I'm wondering, what sort of questions should I be asking of the companies and myself to make the right decision?