I might've made a big mistake. Help

So there is this girl that asked to hang out before and I said I don't have time. Then like 2 weeks later, I thought she is a great and thoughtful person - she helped me integrate into her group of friends and make more friends, and I thought it could be fun hanging out with her - get some positivity and laughter in my life. So the other day, I told her that we should hang out sometimes. We compared schedules and agreed to meet at this farm on Sunday, they have all sorts of animals there.
But the more I think about it, the more I think she believes it's a date, which I really don't want it like that, I just want to hang out as friends, but I realize we will be alone just us 2 together. What can I do?