Hello Harhsa Vardhan!
With most Linux distributions, you can install gcc via a package management system (in Debian, Ubuntu and related systems, use
apt-get, in Red Hat, Fedora and CentOS it would be
yum and in other distros you'll just have to check). That way, the package manager will set everything up for you.
If you downloaded the binaries, you should have an executable file called
gcc, which you can just run with it's (relative or absolute) path, though this isn't the most elegant solution.
Anyway, when it is installed or otherwise available, you can use it like such:
There are other options of course, but you should read about them on the gcc man page (
man gcc), as to explain them here would be too complicated.
Greetings,
Nepomuk