Mapping -Arrows to selecting characters/lines

Question

I started to use vim recently, but I miss the character/line selection methods from other text editors. By default vim maps ,

Answer 1

Vim doesn't bend to that easily in my opinion. The terminal one doesn't even recognize Shift-Up in my case! I thought the v (character-wise selection) or V (line-wise selection) was among the easier concepts to learn about vi/vim.

If this works (can't test right now), this is something you'll want:

" activate visual mode in normal mode
nmap <S-Up> V
nmap <S-Down> V
" these are mapped in visual mode
vmap <S-Up> k
vmap <S-Down> j
" 
" etc...
" similarly <S-Left>, <S-Right> for v

Answer 2

There's an specific option for this: keymodel:

'keymodel' 'km'     string  (default "")
            global
            {not in Vi}
    List of comma separated words, which enable special things that keys
    can do.  These values can be used:
       startsel Using a shifted special key starts selection (either
            Select mode or Visual mode, depending on "key" being
            present in 'selectmode').
       stopsel  Using a not-shifted special key stops selection.
    Special keys in this context are the cursor keys, <End>, <Home>,
    <PageUp> and <PageDown>.
    The 'keymodel' option is set by the |:behave| command.

TL;DR: To enable the behavior you want, use:

set keymodel=startsel

If you also want to leave visual mode when using <Up> or <Down> without <Shift> pressed, you can use:

set keymodel=startsel,stopsel