Row blocks are not exactly intuitive, but I will keep on and get more familiar with how to manipulate them. I use the word ‘manipulate’ advisedly because it feels like that, a bit uncertain as to what is going to happen when I do x instead of y.
‘Row’ is the apposite word for these blocks. I tried to get some subsidiary text to appear below the ‘Talk to the Animals’ text but it insisted on appearing to the side. So I scrubbed it.

Talk to the Animals

Setting the background colour is the standard stuff now of looking over at the right sidebar for ‘Color’ and changing the background colour. Click on the little offset hamburger menu to isolate what yo want to play with . That way you are certain you are highlighting the correct bit. Here’s a screenshot showing the bits.
Can you see how the row is highlighted over on the left, and the text and background are visible for the block on the right,.

By the way, there are also Stack blocks, with which one can stack items vertically.