My handbrake needs adjusting in my Toyota Corolla 1994. Can u please explain how this adjustment is done.

Hello, My usual Brands are Ford products, but Foreign cars usually use simple, less expensive ways to do things. Assuming the brake pads are good, there should be a cable connected to the handbrake. You would usually pull the handbrake up to engage about 1/4 the way to engagement and lock it there.
Then you would go underneath the car and find the cable that stretches from the handbrake lever to a juction with a second cable. There should be an adjusting thread somewhere at this intersection.

With the rear wheels off the ground, you would tighten the nut on the threads of the handbrake cable until you hear rubbing in the rear brakes. Then get inside the car and pull back on the handbrake lever and you should not be able to move the rear wheels with the handbrake set. You then release the handbrake 100% and the rear wheels should turn mostly without noise.

Now if you can not find an adjustment nut under the car, it is possible the handbrake adjustment nut is under the handbrake cover/boot inside the car. Still use the same process of setting the lever 1/4 engaged and tightening the threaded cable until the rear wheels start dragging.

I hope this helps you.

If you have a handbrake, you can remove some screws around the handbrake covering. The screws are sometimes well hidden so you have to look around.
When you get the covering off, there are two adjusting nuts at the rear of the handbrake. Turn the nuts until you can get "5 clicks" on the handbrake to set the brakes.
Some jack up the car while doing this so they can rotate the wheels by hand to feel when the brakes touch the pads.
Hope this helps