If multiple replacement or prevention effects try to modify damage that would be dealt to a creature, the controller of the creature chooses the order in which they apply.

If damage that can’t be prevented is dealt to Stormwild Capridor, it doesn’t get +1/+1 counters for that damage.

If damage that can be prevented is dealt to Stormwild Capridor at the same time as damage that can’t be prevented, it gets +1/+1 counters for the prevented damage before checking to see if it dies from the damage that couldn’t be prevented.