Line numbers

Turn line numbers on

:set nu

Turn line numbers off

:set nu!

Color Scheme

:colorscheme evening

Syntax Highlighting

Turn Syntax highlighting on

:syntax on

Turn Syntax highlighting off

:syntax off

Highlight all search terms

:set hlsearch

https://vim.fandom.com/wiki/Highlight_all_search_pattern_matches

You can add the following to your ~/.vimrc in Linux or ~\.vimrc in Windows so the options are used every time you run vim.

colorscheme evening 
syntax on
set hlsearch
set nu