Shift+arrows Selects multiple adjacent cells. Ctrl+Spacebar Selects the entire column. Shift+Spacebar Selects the entire row.

To edit cell content:

Double-click the cell, or press F2, to enter Edit mode. Insertion point blinks.
Use arrow keys to position insertion point.
Type changes. Use Delete (right) or Backspace (left) to remove characters.
Press Enter to accept.

Alternative: Edit content directly in the Formula bar.

Undo: Reverse last action. Click Undo on Quick Access Toolbar or press Ctrl+Z. Click Undo down arrow to undo multiple actions.
Redo: Restore undone action. Click Redo on Quick Access Toolbar or press Ctrl+Y.

Inserting rows/columns:

Select the row/column where new one(s) should be inserted.
Home > Cells > Insert (arrow) and choose Insert Sheet Rows or Insert Sheet Columns.
Excel inserts new blank row/column and shifts existing content.

Inserting single cell(s) or range:

Select cell(s) adjacent to insertion point.
Home > Cells > Insert (arrow) > Insert Cells.
In Insert dialog box, choose shift option (e.g., Shift cells right, Shift cells down).
Click OK.

Deleting cells/rows/columns:

Select cell(s)/row(s)/column(s) to delete.
Home > Cells > Delete (arrow) and choose Delete Cells, Delete Sheet Rows, or Delete Sheet Columns.

Deleting a block of cells:

Select the block of cells.
Right-click selection and choose Delete....
In Delete dialog box, choose shift option (e.g., Shift cells left, Shift cells up).
Click OK.

Uses the Windows Clipboard.

To move data:

To copy data:

Transpose feature: Home > Clipboard > Paste (arrow) > Transpose. Re-orients data from rows to columns or vice-versa.

To copy only the calculated values, not the formulas:

Select cell(s) with formula(s).
Ctrl+C.
Select destination cell(s).
Click arrow on Paste button (Home tab).
Choose: Values, Values & Number Formatting, or Values & Source Formatting.