The shortcut of Ctrl+Space Bar is to select the entire column. Please refer to "Shift+Space Bar" if you want to use the shortcut to select the row.
Step 1: Click anywhere in the worksheet, e.g., Cell B3;
Step 2: Press the "Ctrl" key and hold it, then press the "Space" bar to select the column B.
If you want to select the whole row, please refer to the shortcut "Shift+Space Bar".
In a practical way, I prefer just to click the column header to select a column.
Step 1: Move the cursor to the column header and you will notice the cursor becomes a black down arrow;
Step 2: Click on the column header and the column is selected.
Step 3: To select more than one columns, click the first column header then drag the mouse cursor to select multiple columns.