Problem with gradle in android studio

I updated android studio and I had to update gradle and others the issue is that this one does not synchronize me, can someone help me configure gradle? Thanks from now.

module: app

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    buildToolsVersion '28.0.3'
    defaultConfig {
        applicationId "app.damian.xxx.miapp"
        minSdkVersion 17
        targetSdkVersion 28
        versionCode 21
        versionName "1.4"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    //compile 'com.google.android.gms:play-services-auth:9.8.0'
    implementation 'com.google.android.gms:play-services-ads:17.1.0'
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.loopj.android:android-async-http:1.4.9'
    implementation 'com.facebook.android:facebook-android-sdk:4.38.1'
    testImplementation 'junit:junit:4.12'

}

//apply plugin: 'com.google.gms.google-services'

module: project

buildscript {
repositories {
    jcenter()
    maven {
        url 'https://maven.google.com/'
        name 'Google'
    }
    //mavenCentral()
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.2.1'

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
    //classpath 'com.google.gms:google-services:3.0.0'
}

}

allprojects {
repositories {
    jcenter()
    maven {
        url "https://maven.google.com"
    }
    maven {
        url 'https://maven.google.com/'
        name 'Google'
    }
}

}

task clean (type: Delete) {     delete rootProject.buildDir }