Select B2 and on the View tab, click Freeze Panes, and the top choice, Freeze
Panes - the description is keep rows and columns visible while the rest of
the worksheet scrolls (based on current selection).  It works the same as the
old Freeze Panes command did and freezes everything to the left and above the
current selection.

Move to cell B2; on the View tab click the down arrow on Freeze Panes icon;
select the first item - to freeze both row & column
Best wishes

Show A1 (to make sure column A and row 1 are visible)
then select B2
Then apply the freeze panes.

You'll be freezing all the rows above that active cell and you'll be freezing
all the columns to the left of that activecell.