You can create a .vimrc file in your home directory. Here is the part of my vimrc file that might help you...
set ts=4 " To set the tab size to 4
nnoremap ; : " Mapping ; to :
set autoindent " Very useful for programming
Hope this helps.
For your other question on ubuntu, I think it just has an alias for vim (like alias vi="vim --compatiable", compatible means, vim would work like a vi than vim). I don't remember ubuntu shipping with vi for years now.