Could not find the task 'build'vs mac version

[Superice2311]

hi everyone, i am a student that learning c++, after i install vs mac i find that i cannot run and debug which shows 'cannot build and debug because the active file is not a c or c++ source file.' Then i find this page and downloaded a vsix file(cpptools-osx-arm64) .After that the problem then is change to "could not find the task 'build'." Thank for help.