Confusion with the Pattern

[Aryn]

I am fairly new to crocheting and am trying to start this baby shirt. To start row one it says “Ch43 hdc in 2nd ch”. Normally they say something like 2nd chain from hook and so on. I’m not sure if I am supposed to start the hdc 2 from the hook or two from where i started

[Granny Square]

Welcome to the 'ville and to crochet!

I'd interpret it as second chain from the hook.  HDC is an 'odd' stitch, it's the only stitch whose turning chain isn't treated consistently, either 1 chain and doesn't count as a stitch (same as SC) or 2 chains and does count as a stitch (sort of like DC for the 'counts as a stitch' part), so this designer is choosing a turning chain of 1, and presumably the turning chain does not count as a stitch.

https://www.craftyarncouncil.com/standards/how-to-read-crochet-pattern  the discussion on this page of this site, under the 'double crochet' section, explains turning chains and how 'counts as a stitch' works.  There's also a menu on the right side to other good stuff for reference--this is all US terms.