Hi,
C64 BASIC is pretty bad. PET BASIC or better yet,
C128 Basic
were a lot better. I suppose with the Simon's Basic cart, C64
BASIC was quite nice.
Sure, you can do a lot with C64 Basic, but everything is a poke,
peek, or a SYS call. It's much nicer when the BASIC you're using
has commands for all that stuff built in.
But we're talking about someone who's learning BASIC from scratch, for which
the C64's BASIC would be perfectly adequate - and there's always the option
of something like "Simon's BASIC" later....
I'd have suggested something running "BBC BASIC" but the Beeb is a fairly
formidable system to understand and the Electron, ISTR, has most of the
electronics inside a ULA so you wouldn't really learn anything useful about
it.
TTFN - Pete.