Ice, ice, ice. And probably some rest. I'm not a doc, but a little ibuprofin (Advil) probably wouldn't hurt, but talk to your parents first please before you take anything. I'm a physical therapist when I'm not a Pole Vaulter
and I can't "prescribe" anything...wouldn't want you to be allergic or something and die.
For icing you can place your heel on a package of frozen vegetables for 15-20 minutes (sit in a chair and gently set your heel down on it)...
or you can 'ice massage' for 7-8 minutes (rub an ice cube on it in circular motions). Don't do it any longer than that (small risk of frost bite if left on longer).
You can ice with either of these methods 2-3 times a day provided you give yourself at least an hour between sessions.
Gentle calf stretching would be good, but if painful, stop! Potentially you could have torn your plantar fascia depending on how you injured it, but hopefully it is just a bruise. Good luck.
Sincerely,
ifavault