Collapsingtoolbar and cardview not formatted correctly

I'm trying to make an android app that has a map on the top half and has a collapsing toolbar with a cardview list. For some reason, I can't seem to make the app work. The toolbar has this huge gap with the title bar when I scroll. Also, the cardview has this huge gap in between each item. The layout looks like this:

It should look somewhat like this:

This is my layout file for the collapsing toolbar:

    <?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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">

    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.appbar.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="top"
            android:fitsSystemWindows="true"
            app:contentScrim="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:statusBarScrim="@null"
            app:titleEnabled="false"
            android:minHeight="?attr/actionBarSize" >

            <fragment
                android:id="@+id/mapView"
                android:name="com.mapbox.mapboxsdk.maps.MapFragment"
                android:layout_width="match_parent"
                android:layout_height="350sp"
                android:apiKey="@string/mapbox_api_key"
                android:clickable="true"
                android:enabled="true"
                android:focusable="true"
                app:layout_collapseMode="parallax" />

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/appbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:layout_marginBottom="48dp"
                android:gravity="top"
                app:layout_collapseMode="pin"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:title="" />

            <com.google.android.material.tabs.TabLayout
                android:id="@+id/tabLayout2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="parent">

                <com.google.android.material.tabs.TabItem
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/stats" />

                <com.google.android.material.tabs.TabItem
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/news" />

                <com.google.android.material.tabs.TabItem
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/symptoms" />

                <com.google.android.material.tabs.TabItem
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/safety" />

            </com.google.android.material.tabs.TabLayout>


        </com.google.android.material.appbar.CollapsingToolbarLayout>
    </com.google.android.material.appbar.AppBarLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        app:layout_behavior="@string/appbar_scrolling_view_behavior">


        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerView2"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="parent"
            tools:listitem="@layout/list_view">

        </androidx.recyclerview.widget.RecyclerView>


    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.coordinatorlayout.widget.CoordinatorLayout>

This is the layout for the list itself:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.cardview.widget.CardView
        android:id="@+id/card_view"
        android:layout_gravity="center"
        android:layout_width="200dp"
        android:layout_height="200dp"
        card_view:cardCornerRadius="4dp">

        <TextView
            android:id="@+id/info_text"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    </androidx.cardview.widget.CardView>

</LinearLayout>

I'm sorry if this looks bad, I'm not really that experienced at mobile app development.

I can't figure out why it's not working right because all the pages I read and tutorials did it this way, even the Google developer reference. Could you please help me find out what I'm doing wrong?

Thank you!