How do I apply KVL in this circuit?
You must decide in advance whether you are going to say that a voltage is positive in the KVL equation when you move from its negative terminal to its positive terminal, or that it is positive in the KVL equation when you move from its positive terminal to its negative terminal. Having made that decision you must be consistent with all voltages as you go around the loop.

First, let's recognize that the voltage across the resistor is positive at the right end of the resistor, and VCE is positive at the collector.

If I go counterclockwise starting at the transistor's emitter, and I say that a voltage increase is positive (moving from negative terminal to positive terminal) then I get this equation:

\$V_{CE} + R2\times I_C - 8 = 0\$

If I go CCW but say that a voltage decrease is a positive term then I get:

\$ -V_{CE} - R2\times I_C + 8 = 0\$

These terms are algebraically equivalent, so it doesn't matter which way you choose to write the voltage terms as long as you are consistent.