Could you please clarify for me? If I activate an ability that has a cost and then copy it, do I need to pay the cost again for the copy to resolve?

For example, the ability of [[Isareth, the Awakener]]. If I decide to attack and pay X mana to reanimate a creature, do I also have to pay again if I copy the ability? And if so, am I able to pay a different amount, considering that the source of the copying states, “You can choose new targets for the copy”?

A second question is for a card like [[Drana, Liberator of Malakir]]. If she deals direct damage and her ability triggers, would the +1/+1 counter be placed on each attacking creature, including herself, twice, were I to copy it?

I’m not sure if it’s necessary to mention, but I am new to this, I am using [[The Peregrine Dynamo]] to copy those abilities.

Thank you for your help in clarifying this!