If you are good with animals, you can be allowed to volunteer at Lehigh County Humane Society animal shelter. They give you simple tasks like walking the animals, playing with them or feeding them. I would also advise you to contact No Kill Lehigh Valley shelter and inquire about volunteering. To get their contacts, visit http://www.nokilllv.org/.
Well depending on the shelter, if they will allow a 14 year old to volunteer there are quite a few things. Exercising/Play/Socializing the dogs, cleaning out kennels, feeding and watering the animals, etc.