Help with colorwork chart

I have done colorwork before and knitted from charts but I’m really having trouble with this one. The pattern is called Good Egg Sweater and is a paid for pattern. chart A at bottom on row 1 up to row 20 I don’t understand what it means by repeat. Yarn A or yarn B?And why aren’t the blocks colored in. It almost looks like you’re supposed to skip them but that can’t be right! Please help. My first sweater! Thank you

You’re correct, skip those blocks. There aren’t stitches there yet. Later, in rows 2, 11 and 21 there are increases that will make those sts.
There are 6sts in row 1: 3 in yarn A, 1 in yarn B and 2 in yarn A. Then the stitches repeat. (6x36=216)

Oh! Wow, thank you so much!