I'm 13 years old and I was wondering how I could help and volunteer?

If you go to their website they have an online form form volunteering

I would suggest your parent call and speak on your behalf to find out what would be possible for you. One thing I could think of would be to collect dry and canned dog food, toys, cat litter, cat food things that would help the animals. Maybe you could read to the animals. Congratulations on your willingness to help animals.

You'll need your parent with you and do the volunteer class on Saturdays. Once you're 16 you can be by yourself