Insert Column from Ribbon, on the Home tab, in the Cells group, click Insert, and then click Insert Sheet Column. EXCEL will insert a column immediately left of the selected column.
Picture 1. Before insert a column
Picture 2. After insert a column
Insert column - Ribbon, INSERT button, steps:
Select a column header
in this example B.
Ribbon.
Home tab.
Cells group.
Click Insert button .
Click Insert Sheet Column.
For each selected column EXCEL will insert new column.