Sometimes your data isn't as broken down, as granular, as you'd like.
What you typically want, for the most power over your data, is this.
Here's how to split it automatically, not manually.
First, you need to take out that space between the comma and the first name. Select all the cells in that name column.
Choose Edit > Find and Replace. Type a comma immediately followed by a space in the Search For field and just type a comma in the Replace With field. Click More and select Current Selection Only.
Then click Replace All.
And you'll see the data looks like this.
Now you're ready to split it at the comma. First, be sure that you have an empty column to the right of the Name column, to put the first name and initial into. Then click on the column header to select the whole column.
Choose Data > Text to Columns.
Select the comma, but nothing else. You'll see a preview of how it will be split.
Then click OK and you'll see the actual data split.