Start with your platform (if you don't have one, there will be a blog on that later) or what charities you are already familiar with. Visit different charity's websites and look for "Volunteer Opportunities" or "Get Involved" (you should find this from the search bar or the bottom of the website). From there you should be able to find what opportunities are available and what age restrictions there are. Some charities have updated their site with Covid information and if there are still volunteer opportunities or additional suggestions.
It isn't always easy to find volunteer opportunities for every age group. Sometimes there are age requirements that prevent younger girls from volunteering but if you keep searching you will find something. You can also ask your local and state queens and directors for advice. And while it isn't easy, it is definitely worthwhile when you find the right organizations to get involved with.
There are a lot of opportunities out there, you just have to find them. Although we're in a pandemic and there are limitations for in-person opportunities, you can still find ways if you do your research and get creative. And when in doubt, look to your pageant sisterhood for ideas!