Check whether curl has been installed or not.
which curl
if curl is installed, it will give you the path.
If not installed,
sudo apt-get install curl
Now, use
This will download the installer to the current directory.
Now,
sudo bash vestacp.sh
This will install vesta. First it will ask for e-mail ID. Enter a valid e-mail ID.
Then, it will ask for host. If want to use default, presee ENTER.
Then, vesta will be installed.
It may take 15 minutes to 30 minutes.