1 - (8 to the second power + 6)

Which do I do first 8+6 the then exponent or Vice versa?

You would need to do it vice versa

If you follow pemdas, you would first do what is inside the parentheses, and then the exponent. In this case your exponent is inside the parentheses so you would simplify the exponent first, and then solve the rest of the problem (multiply/divide, add/subtract).

1 - (8²+6)

1 - (64+6)

1-70

-69