Knitting 2x2 rib collar to join two pieces? Dog jumper help!

So I’ve been trying to knit my first proper project (that isn’t a simple scarf!) And I’ve hit a hurdle. I’ve currently stitched the back of the jumper and the chest piece. The back is on a stitch holder, the chest on my needles, both ended on a WS row so the next row to stitch would be a RS. The back is 58 sts, the chest 10.
It is here I get muddled. The pattern states “cast on 8 sts. Begin by working over sts cast on, work in 2x2 rib across chest sts, continue in 2x2 rib across back sts on holder -76 sts”.
Does this mean that I cast on 8 sts on my chest piece, and then just 2x2 rib, and when i reach the end continue on to the back piece without stopping? Knitting stitches off the holder so that I end up with one piece 76 sts long?
Sorry if this isn’t explained well. I’ve been knitting a very short time (not even a year) and I’d love to be able to finally finish my first proper project so any help would be much appreciated!

Welcome to the forum!
Yes, that’s exactly the way to do it. Cast on, knit across the cast on, then the chest sts and finally the back sts.
Here’s a video for casting on at the end of a row in case you need it. You can take the needle with the chest sts and cast on as shown

Hi,
Thank you so much! I thought it must be, I’ve just put a good few hours (cough days cough) into this and really didnt want to ruin it.
Thank you!