Fields overlapped and turns and some button

Good Night!

I'm starting in the art of Android Studio and I'm getting a lot of it and I'm looking for help.

I have a login form (Activity).

2 fields: login and password and 1 button

When compiling the fields lie one over the other

Here's the xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Login">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="LOGON"
        tools:layout_editor_absoluteX="162dp"
        tools:layout_editor_absoluteY="16dp" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="Usuário"
        tools:layout_editor_absoluteX="83dp"
        tools:layout_editor_absoluteY="61dp" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPassword"
        tools:layout_editor_absoluteX="80dp"
        tools:layout_editor_absoluteY="129dp" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Login"
        tools:layout_editor_absoluteX="147dp"
        tools:layout_editor_absoluteY="201dp" />
</android.support.constraint.ConstraintLayout>

And the .java

package carcleo.com.cadastrodeclientes;

import android.app.Activity;
import android.os.Bundle;

public class Login extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);
    }
}

What am I missing?