How do I install ERPNext

hii sir i want to do fresh installation pls provide me commands with prerequisite
thanks

Follow the instructions here: bench/README.md at master · frappe/bench · GitHub

You can also look at this one

Just Install Ubuntu 14.X or 16.X and follow the instruction

sudo apt-get update
sudo adduser frappe
sudo usermod -aG sudo frappe
su - frappe
wget https://raw.githubusercontent.com/frappe/bench/master/playbooks/install.py
sudo python install.py --production