ERPNext Tutorial for Beginner?

Hi, All
I’m new in ERPNext come from Odoo…
my some question is …
what is difference between Frappe and ERPNext
where i can find functional as well as technical training of ERPNext
how i can customized existing module
how i can create new module
how i can create new reports
how i can use ERPNext API for E-Commerce Websites

erpnext youtube tutorials

erpnext user manul/official documentation