A lot of VPNs are owned or connected to Israeli intelligence agencies or other assorted shell companies.
Mullvad is your best bet but VPNs don't make you private. In fact they should just be called Virtual LAN networks. Most of your traffic on the clearnet is encrypted already via HTTPS and VPNs only obfuscate your IP address from the website you're connecting to. A lot of the fuckery comes from the nonfree clientside JS code that is executed on a lot of websites that can track you as well as nonfree web browsers.
VPNs won't protect you against bad digital practices.
A much better approach to digital privacy is to make sure that your org can function entirely on free software that respects your freedoms. Example: instead of organizing via Discord, Social Media, etc. you can organize via XMPP or Matrix which can be deployed by your org if needed. Instead of creating documents via M$ Office or Google Docs you can use a office suite like LibreOffice and store everything locally and only share copies when needed. Instead of meeting over Zoom you can meet over Jitsi Meet.
This in my opinion, is far more impressive and worthwhile task than asking your members to pay for a VPN. It actually educates your org on good computing practices rather than security theatre that you'll have to pay into.
There's a big fucking reason why YouTubers can sponsor VPNs but no one seems to be aware of FOSS.