I actually work for a fundraising site. MoveYourMountain.org They're great for teams and organizations. Compare their fees with others (theirs is only 4% and you get a "branded page") That's a webpage with only YOUR PTO's info on it (none of our links or advertisements). We also have an option for you to run an "on-going" campaign. That's where you can have people sign up to donate do much $$ a month instead of a big lump sum ($10 a month seems easier for many than a check for $120).
Anyway...I do their social media, so I'd be glad to help you get a page started and give you tips on how to promote it to you parents and community.
Does anyone have experience using an online crowdfunding website such as fundly.com or gofundme.com to raise money for their PTO? If so, could you share if it is a viable source for fundraising and if you had success or not?