Need recommendations for good membership form plugin

I help to run a non-profit museum’s website, we need to get a section of our website where people can pay for museum memberships with their credit card, people would fill out personal information and billing information and it would also be submitted securely on the website. Since we’re a non profit, it would be great if there was a free plugin that could do this.

I’m looking for recommendations from people who have used similar membership type forms before… I’ve searched online and just get tired of installing something, having it not work, have to uninstall and try something else… Hope somebody has a good recommendation! Thank you.

Here is the link to our membership page now: https://www.friendsofthenysmilitarymuseum.com/members/