How to crochet pattern abbreviations?

I'm fairly new to crochet and have come across a pattern that when I followed it, it created a funny looking result and nothing like the picture! The section of the pattern that's giving me trouble is as follows: "*Miss next 3 ch. 1 sc in next ch. Ch 3. 1 dc in each of next 3 ch. Rep from *" The part specifically is after you single crochet in next chain, then the "Ch 3. 1 dc" etc. Does that mean to make 3 chains in the last single crochet and then double crochet in those 3 newly created chains. Sorry if this is confusing! The pattern that I'm trying to create is called "shells".

You said "make 3 chains in the last single crochet." Well, you don't chain "in" another stitch. Just like when you start your project with a series of chain stitches, this series of 3 chain stitches should create a small chain coming out of your last stitch. So you just finished your sc and you have one loop of yarn on your hook. Without poking your hook through any of your previous work, simply hook your yarn (coming from the skein or ball) and pull through - just like your first row. Do that 2 more times, then you do the next 3 dcs. The 3 chains form a "loop" above/between the sc to the first dc.This loop is probably going to be the base or "vortex" of a shell, which you will create in the next row.

make the 3 chains then act like there not even there, just make a double in the next 3 chains. it will leave a little space where you will make the shells in the next row.