How to control steppers motors

Hi guys i need help
I have 2 steppers motors and i need help to control
Example
If (butoonPin1==HIGH);
Stepper1 turne 90°
If(buttonPin2==HIGH);
Stepper2 turne 180°

There is not ehough information to help you. What stepper? What driver? What Arduino? How are the Arduino and stepper powered?

Stepper basics.

I use bipolar steppers and l293d driver

If the hardware is not done right the software cannot make up for it.

I know a little more than I did,but still not enough. Can you post a data sheet for the motors or their
specifications.

The L293 driver is not suitable for modern stepper motors. It is ancient and inefficient technology, has no coil currentlimit and is not rated for very much current. Depending on your motor, you would be advised to consider more modern stepper drivers. Pololu has a good selection.

The software is pretty easy to write.
If Those 293 drivers will "work" with your motors the Stepper library examples should get you started.

Better yet get a modern step/dir driver and use the simple stepper code to test.