Let us see, how to install nodejs first
Go to 'https://nodejs.org/en/download/' and download LTS version of nodejs.
Now run the nodejs installer.After installation complete, make sure that it is installed correctly.
Go to command prompt and type 'C:\\users\\user1> node –v'
It will show the installed version of nodejs in your system.
npm:The node package manager comes along with nodejs itself.
To check the installed version of npm:
Give the command as 'C:\\users\\user1>npm –v'
To install typescript package
Go to command prompt and type
'C:\\users\\user1>' npm install typescript g
‘g’ means globally u can use this typescript package globally in any folder.
How to install angular cli?
Go to command prompt and type Npm install (at the rate of) 'angular//cli –g'