How do i open my 1990 chevy lumina hood from

You have to engage the "hood release" from inside the car...
(lower left, under the dash, on side panel.)

The hood must "pop" up enough for you to reach under the hood at the center front. There is a lever an inch to the right of the center of the front of the hood. Swing that lever up and to the left about 2 inches.
The hood will pop open.

As you lift the hood, notice the horizontal metal rod that holds the hood up. While holding the hood open with one hand, lift the metal rod and insert it into the slot (hole) on the hood, beign careful that it is the correct slot on the hood.

Note: If the hood does not pop up when you engage the inside latch, then push down on the hood (it may be stuck) .... don't push down gently... give it a good push and release.
It will pop up.

I know that you knew some of this, but the detail may help others.
Hope this explains it for you.