Pattern help connecting in the round

I'm new to crocheting. I don't understand which stitches these are referring to when joining round to round:

The shell pattern is 2 dc, ch 1, 2 dcs

Chain 5 and join with sl st in first chain to form a ring - No problem here.

Round 1- Ch 3, dc in ring, ch 1, [work 2 dcs in ring, chain 1] three times, join with sl st in top of beginning ch 3; 8 dcs and 4 ch-sps. Question: which is the top stitch of beginning ch 3?

Round 2 - Sl st to ch-sp, ch 3, work 1 dc, ch1, 2 dcs in same ch-sp (SH made) * work SH in next ch-sp: repeat from * around, join with sl st in stop of beginning ch-3; 4 shells. Questions: at beginning of row - what does it mean to "sl st to ch-sp" and at end of row - "sl st in stop of beginning ch-3"?

Round 3 - "Sl st to ch-sp of next SH"

Thanks for help provided