Project is not running in Angular

My project in Angular is not getting build. When I run the app(ng serve -o), it's showing this message:

`An unhandled exception occurred: Cannot find module '@angular-devkit/build-angular/package.json' Require stack:

• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\node_modules@angular-devkit\architect\node\node-modules-architect-host.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\node_modules@angular-devkit\architect\node\index.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\models\architect-command.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\commands\serve-impl.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\node_modules@angular-devkit\schematics\tools\export-ref.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\node_modules@angular-devkit\schematics\tools\index.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\utilities\json-schema.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\models\command-runner.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\lib\cli\index.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\lib\init.js
• C:\Users\User\AppData\Roaming\npm\node_modules@angular\cli\bin\ng See "C:\Users\User\AppData\Local\Temp\ng-2zf3VF\angular-errors.log" for further details.`

and When I try to install npm -

`npm ERR! code 1

npm ERR! path H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-sass

npm ERR! command failed

npm ERR! command C:\Windows\system32\cmd.exe /d /s /c node scripts/build.js

npm ERR! Building: C:\Program Files\nodejs\node.exe H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-gyp\bin\node-gyp.js rebuild --verbose --libsass_ext= --libsass_cflags= --libsass_ldflags= --libsass_library=

npm ERR! gyp info it worked if it ends with ok

npm ERR! gyp verb cli [

npm ERR! gyp verb cli 'C:\Program Files\nodejs\node.exe',

npm ERR! gyp verb cli 'H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-gyp\bin\node-gyp.js',

npm ERR! gyp verb cli 'rebuild',

npm ERR! gyp verb cli '--verbose',

npm ERR! gyp verb cli '--libsass_ext=',

npm ERR! gyp verb cli '--libsass_cflags=',

npm ERR! gyp verb cli '--libsass_ldflags=',

npm ERR! gyp verb cli '--libsass_library='

npm ERR! gyp verb cli ]

npm ERR! gyp info using [email protected]

npm ERR! gyp info using [email protected] | win32 | x64

npm ERR! gyp verb command rebuild []

npm ERR! gyp verb command clean []

npm ERR! gyp verb clean removing "build" directory

npm ERR! gyp verb command configure []

npm ERR! gyp verb check python checking for Python executable "c:\python27\python.exe" in the PATH

npm ERR! gyp verb which failed Error: not found: c:\python27\python.exe

npm ERR! gyp verb which failed at getNotFoundError (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:13:12)

npm ERR! gyp verb which failed at F (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:68:19)

npm ERR! gyp verb which failed at E (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:80:29)

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:89:16

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\isexe\index.js:42:5

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\isexe\windows.js:36:5

npm ERR! gyp verb which failed at FSReqCallback.oncomplete (fs.js:183:21)

npm ERR! gyp verb which failed c:\python27\python.exe Error: not found: c:\python27\python.exe

npm ERR! gyp verb which failed at getNotFoundError (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:13:12)

npm ERR! gyp verb which failed at F (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:68:19)

npm ERR! gyp verb which failed at E (H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:80:29)

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\which\which.js:89:16

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\isexe\index.js:42:5

npm ERR! gyp verb which failed at H:\JavaScript\Practise\Angular\gkb-app\node_modules\isexe\windows.js:36:5

npm ERR! gyp verb which failed at FSReqCallback.oncomplete (fs.js:183:21) {

npm ERR! gyp verb which failed code: 'ENOENT'

npm ERR! gyp verb which failed }

npm ERR! gyp verb could not find "c:\python27\python.exe". checking python launcher

npm ERR! gyp verb could not find "c:\python27\python.exe". guessing location

npm ERR! gyp verb ensuring that file exists: C:\Python27\python.exe

npm ERR! gyp ERR! configure error

npm ERR! gyp ERR! stack Error: Can't find Python executable "c:\python27\python.exe", you can set the PYTHON env variable.

npm ERR! gyp ERR! stack at PythonFinder.failNoPython (H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-gyp\lib\configure.js:484:19)

npm ERR! gyp ERR! stack at PythonFinder. (H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-gyp\lib\configure.js:509:16)

npm ERR! gyp ERR! stack at callback (H:\JavaScript\Practise\Angular\gkb-app\node_modules\graceful-fs\polyfills.js:295:20)

npm ERR! gyp ERR! stack at FSReqCallback.oncomplete (fs.js:183:21)

npm ERR! gyp ERR! System Windows_NT 10.0.17763

npm ERR! gyp ERR! command "C:\Program Files\nodejs\node.exe" "H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-gyp\bin\node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="

npm ERR! gyp ERR! cwd H:\JavaScript\Practise\Angular\gkb-app\node_modules\node-sass

npm ERR! gyp ERR! node -v v14.16.1

npm ERR! gyp ERR! node-gyp -v v3.8.0

npm ERR! gyp ERR! not ok

npm ERR! Build failed with error code: 1

npm ERR! A complete log of this run can be found in:

npm ERR! C:\Users\User\AppData\Local\npm-cache_logs\2021-05-02T02_06_34_403Z-debug.log ` I tried several solution, but those are not working. Please have a look. Thank you