Cannot connect emulator in Android Studio on MacOS-CodePudding

I have a problem with the emulator that I cannot run my app on it. A few months ago, I still can open my old projects and run them on an emulator. After a few months, I come back with a new project and now I can open the emulator but it is not connected with my project (with my old projects too).

I see there are errors saying faild to start adb when I open my emulator and another notification says daemon is terminated. I google those to find solutions but nothing helps.

Here is my flutter doctor -v

or found issues in 3 categories.
Macbooks-MacBook-Pro-3:learning_bee quanan$ flutter doctor -v
[✓] Flutter (Channel dev, 2.3.0-24.0.pre, on Mac OS X 10.14.6 18G2022 darwin-x64, locale en-US)
    • Flutter version 2.3.0-24.0.pre at /Users/quanan/Downloads/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 2b9537c783 (5 months ago), 2021-06-11 22:11:53 -0700
    • Engine revision ddbac024d1
    • Dart version 2.14.0 (build 2.14.0-188.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/quanan/Library/Android/sdk
    • Platform android-30, build-tools 31.0.0
    • Java binary at: /Library/Java/JavaVirtualMachines/jdk1.8.0_271.jdk/Contents/Home/bin/java
    • Java version Java(TM) SE Runtime Environment (build 1.8.0_271-b09)
    • All Android licenses accepted.

[!] Xcode - develop for iOS and macOS
    ✗ Xcode installation is incomplete; a full installation is necessary for iOS development.
      Download at: https://developer.apple.com/xcode/download/
      Or install Xcode via the App Store.
      Once installed, run:
        sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
        sudo xcodebuild -runFirstLaunch
    ! CocoaPods 1.9.3 out of date (1.10.0 is recommended).
        CocoaPods is used to retrieve the iOS and macOS platform side's plugin code that responds to your plugin usage on the Dart side.
        Without CocoaPods, plugins will not work on iOS or macOS.
        For more info, see https://flutter.dev/platform-plugins
      To upgrade see https://guides.cocoapods.org/using/getting-started.html#installation for instructions.

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[!] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from: