react-native run android

Olá galera estou iniciando um projeto com react-native mas estou tendo sérios problemas até o momento em tentar rodar o código no emulador do android studio, até o momento ainda não fiz mudanças nos arquivos do projeto, estão do jeito que foram instalado. Se alguém puder me ajudar estarei grato, segue o erro :

Starting a Gradle Daemon, 1 incompatible and 1 stopped Daemons could not be reused, use --status for details

FAILURE: Build failed with an exception.

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What went wrong: A problem occurred configuring project ':app'.

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SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project's local properties file at '/home/eliascmendhes/my_pet/android/local.properties'.

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Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

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Get more help at https://help.gradle.org

BUILD FAILED in 28s

error Failed to install the app. Make sure you have the Android development environment set up: https://facebook.github.io/react-native/docs/getting-started.html#android-development-environment. Run CLI with --verbose flag for more details. Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081

FAILURE: Build failed with an exception.

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What went wrong: A problem occurred configuring project ':app'.

>

SDK location not found. Define location with an ANDROID_SDK_ROOT environment variable or by setting the sdk.dir path in your project's local properties file at '/home/eliascmendhes/my_pet/android/local.properties'.

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Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

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Get more help at https://help.gradle.org

BUILD FAILED in 28s

at checkExecSyncError (child_process.js:601:13)
at execFileSync (child_process.js:621:13)
at runOnAllDevices (/home/eliascmendhes/my_pet/node_modules/@react-native-community/cli-platform-android/build/commands/runAndroid/runOnAllDevices.js:74:39)
at buildAndRun (/home/eliascmendhes/my_pet/node_modules/@react-native-community/cli-platform-android/build/commands/runAndroid/index.js:158:41)
at then.result (/home/eliascmendhes/my_pet/node_modules/@react-native-community/cli-platform-android/build/commands/runAndroid/index.js:125:12)
at <anonymous>
at process._tickCallback (internal/process/next_tick.js:188:7)