Help me

Hello, me and some friends are in a competition and we are trying to get the robot the straighten itself using two ultrasonic sensors, both are located on the right side of the robot in a straight line.
if anyone can help me it would be very considerate.

I am not entirely sure what you mean. I am guessing this is an autonomous drivetrain that you are attempting to align with a wall. If so, using ultrasonic will not work since the walls are clear(at least where I am). Nevertheless, if they weren’t I would compare the values and self correct using PID. If you don’t know PID then I would probably just do something like this until you can implement PID, it would be essentially the same except instead of defining the motor values as constant you would call your PID function or task:

int ultrasonicDifference = SensorValue[sonarFront] - SensorValue[sonarBack];

if(ultrasonicDifference > 5) 
motor[leftSide] = 63;
motor[rightSide] = 0;
else if(ultrasonicDifference < -5)
motor[leftSide] = 0;
motor[rightSide] = 63;
//run normally

The ultrasonic sensor uses sound waves, not light waves, so the transparent field perimeter is a perfectly good thing to use with the ultrasonic.