How can I draw all possible stereoisomers for 2-chloro-3-hexanol?

Step 1. Draw the bond-line structure for 2-chlorohexan-3-ol.

Step 2. Identify the chiral centres.

There are two chiral centres: C-2 and C-3. So, there are ##2^2 = 4## stereoisomers.

Step 3. Convert the bond-line structure to four wedge-dash structures.

The combinations will be WW, WD, DW, DD (W = wedge; D = dash).

And there you have them.