added subsystem folder and constants, in the subsystem I added drivetrain.java and in constants I added drivetrainconstants.java

src/main/java/frc/robot/constants/DrivetrainConstants.java

@@ -0,0 +1,9 @@
+package frc.robot.constants;
+
+public class DrivetrainConstants {
+   public static final int kleftFrontPWN = 0;
+   public static final int kleftRearPWN = 1;
+   public static final int kRightfrontPWM = 2;
+   public static final int kRightRearPWM = 3;
+
+}

src/main/java/frc/robot/subsystems/Drivetrain.java

@@ -0,0 +1,48 @@
+package frc.robot.subsystems;
+
+import java.util.function.DoubleSupplier;
+
+import com.fasterxml.jackson.databind.ser.std.NumberSerializers.DoubleSerializer;
+
+import edu.wpi.first.wpilibj.drive.DifferentialDrive;
+import edu.wpi.first.wpilibj.motorcontrol.Victor;
+import edu.wpi.first.wpilibj.motorcontrol.VictorSP;
+import edu.wpi.first.wpilibj2.command.Command;
+import edu.wpi.first.wpilibj2.command.SubsystemBase;
+import frc.robot.constants.DrivetrainConstants;
+
+public class Drivetrain extends SubsystemBase {
+    private VictorSP leftFront; // tells the motors how much power they use
+    private VictorSP leftRear;
+    private VictorSP rightFront;
+    private VictorSP rightRear;
+
+    private DifferentialDrive drive;
+    
+    public Drivetrain() {
+        leftFront = new VictorSP(DrivetrainConstants.kleftFrontPWN);
+        leftRear = new VictorSP(DrivetrainConstants.kleftRearPWN);
+        rightFront = new VictorSP(DrivetrainConstants.kRightfrontPWM);
+        rightRear = new VictorSP(DrivetrainConstants.kRightRearPWM);
+
+        leftFront.addFollower(leftRear);
+        rightFront.addFollower(rightRear);
+        rightFront.setInverted(true);
+
+        drive = new DifferentialDrive(leftFront, rightFront);
+
+    }
+
+    public Command driveArcade(DoubleSupplier xSpeed, DoubleSupplier zRotation) {
+        return run(() -> {
+            drive.arcadeDrive(xSpeed.getAsDouble(), zRotation.getAsDouble());
+        });
+
+    }
+    public Command driveTank(DoubleSupplier leftspeed, DoubleSupplier rightspeed) {
+        return run (() -> {
+            drive.tankDrive(leftspeed.getAsDouble(), rightspeed.getAsDouble());
+        });
+    }
+
+}