Hi and welcome!
These directions can be confusing. I like to write them out and the cross them off as I do them.
Call the next row, row 1.
For the raglan armhole decreases, dec on rows 1,5, and then 7,9,11,13,15,17,etc.
For the neck decreases, dec on row 1,5,9,13,17,21, and 25.
Congratulations on the new grandchild. That's fabulous news.