Screen layout problems android. How to solve the problem of incorrect display of data?

Question

Java

The guys ran into two problems because of their inexperience, let's say so. First, the data is not displayed correctly in the emulator, tell me how you can solve this problem.

And the second problem, padding are by default, you can see on the layout, how can I get rid of them? Thanks in advance)

<?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="com.example.user.db.MainActivity">

    <RelativeLayout
        android:layout_width="368dp"
        android:layout_height="551dp"
        android:background="@color/test3"
        tools:layout_editor_absoluteX="8dp"
        tools:layout_editor_absoluteY="8dp">

        <TextView
            android:textColor="@color/test4"
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/drivingschoolcrm"
            android:textSize="30sp"
            tools:layout_editor_absoluteX="90dp"
            tools:layout_editor_absoluteY="60dp"
            android:layout_above="@+id/button2"
            android:layout_centerHorizontal="true"
            android:layout_marginBottom="53dp" />

        <Button
            android:onClick="bLog"
            android:textSize="20sp"
            android:textColor="@color/test4"
            android:background="@drawable/rounded_button"
            android:id="@+id/button2"
            android:layout_width="250dp"
            android:layout_height="wrap_content"
            android:text="@string/main_log"
            tools:layout_editor_absoluteX="146dp"
            tools:layout_editor_absoluteY="137dp"
            android:layout_marginBottom="43dp"
            android:layout_above="@+id/button3"
            android:layout_centerHorizontal="true" />

        <Button
            android:onClick="bReg"
            android:textSize="20sp"
            android:textColor="@color/test4"
            android:background="@drawable/rounded_button"
            android:id="@+id/button3"
            android:layout_width="250dp"
            android:layout_height="wrap_content"
            android:text="@string/main_reg"
            tools:layout_editor_absoluteX="146dp"
            tools:layout_editor_absoluteY="235dp"
            android:layout_alignParentBottom="true"
            android:layout_alignStart="@+id/button2"
            android:layout_marginBottom="203dp" />

    </RelativeLayout>


</android.support.constraint.ConstraintLayout>