PHP Carbon get toDay date by formatting date

$today = Carbon::today()->toDateString();

You can format the output like this: Carbon::now()->format('Y-m-d');

Have you read documentation? There are plenty of examples how to do it

$dt = Carbon::now()

var_dump($dt->toDateTimeString() == $dt);          // bool(true) => uses     __toString()
echo $dt->toDateString();                          // 1975-12-25
echo $dt->toFormattedDateString();                 // Dec 25, 1975
echo $dt->toTimeString();                          // 14:15:16
echo $dt->toDateTimeString();                      // 1975-12-25 14:15:16
echo $dt->toDayDateTimeString();                   // Thu, Dec 25, 1975 2:15 PM

// ... of course format() is still available
echo $dt->format('l jS \\of F Y h:i:s A');         // Thursday 25th of December 1975 02:15:16 PM