Im trying to control 2 stepper motors using the function read().
There is no function read(). There are several classes that have read() methods. I'm being picky here, because it is important to know which class' read() method you are trying to use.
I must give in serial monitor 2 values , one for each motor ,and they must move to the specified angle (go-to mode). My code doesn't seem to work...
Stepper motors do mot move to specific angles. They step a specified number of times. If you compute the correct number of steps, the stepper motor will rotate to the correct position.
if (Serial.available()) {
delay(1000);
You know that there is serial data available. What are you waiting for?
stepper1.step(Serial.read());
Serial.read() reads one byte. It is unlikely that the character/byte you read is the number of steps to step. What is sending the serial data?
Serial.println(" stepper1:");
Serial.print(Serial.read());
You checked that there was at least one byte to read. You read that one byte. Now, you are reading and printing another byte. Why?
Reading serial data pops the value off a stack (effectively). It is no longer available to be read again.
buttonState == LOW;
This is performing a (useless) comparison, not an assignment. You probably don't need to do this, since you (presumably) assign buttonState a new value when loop() executes again.