First of all, maybe it would be best to have a plan, instead of just putting out word that you have land (and possibly that hospital building?) for people to shelter on. That is, and you will likely need assistance on this part, set things up beforehand, so when people get there they are completely humanized again. Showers, whatever portable set-up you can figure out to greet people so they can get clean before they even settle in, church ladies there to help women with their children, clean clothes that have been donated for all sizes including the extra extra large, a medical team, a camp of tents already set up including cots with clean bedding. Consider a table where people sign in, their tents are set up like a neighborhood and numbered so people can get mail, through a church address, and have it delivered to the camp from there.
Also consider a team of church ladies, and men of course, to go around town and collect book donations, books for children, books for adults, too. Have people, maybe a student volunteer group, to go around a read stories to groups of little children. Also have kids toys donated.
You will need some educator volunteers, and this could come from among the retired community, to set up classes, for the kids until they can get worked into the local school system, and for the adults on something that might be of interest, a diversion from the topic of homelessness.
To that end also, why not a home grown outdoor theatre? A screen for projected movies - the pools used to put on outdoor movies in the summer where I grew up so it can't be that involved - movies of good cheer, please. And, a stage, because what better diversion than for people to perform for one another? People love that.
Also, have people form volunteer groups, for example, it might be cool to have one group to take care of laundry needs for everyone, and set that up like a real business, only a free one, with professional touches like folded laundry and bagged and numbered to get back to the right customer.
I'm a little shy of getting into an idea for donations that I have, it sounds awfully elaborate. But people should have nice things. I hope everyone will donate some nice things, and it would be nice to have a little "shopping" thing set up, it would be great to have clothing sorted so folks can find their size and all. Only clean, nice clothes, appropriate for the season, none of those pilly fleeces and stinky old wool suits, please. Jewelry, too, but maybe put that idea in with the crafts ideas I mention below.
Back to more earthy matters, you have got to get some experienced advice regarding amount of food, amount of water, and toilet and shower facility capacities and the like. These have got to be taken care of so people feel human and clean. Have some nice shampoos and conditioners donated, and oils and lotions too. Make people feel rich!
There are all sorts of volunteers like massage therapists and counselors that love to nurture people in their specific ways after disasters.
A great thing, an extra thing for the people to get together and donate, would be phones. How can people get phone service on your fifty acres.
How about camp fires, and roasted marshmallows. I'm not kidding. I think this stuff could make all the difference in the world between a functioning and happy-given-the-circumstances camp, and one that descends in tone if even because people are miserable and crying and that affects everyone's mood.
This could be a great opportunity, too, for folks to set up craft collectives and the like. Find who is talented at something that they could teach to some others. This could be a hot commodity soon, mark my words. It could happen, if people catch on to this idea, that craftwork from hurricane refugee camps is the thing to have, and it can be found on the internet on various sites that volunteers create and coordinate the buying and selling with the camps.
Okay, also you got people there with any kind of musical talent, don't forget to ask around, who needs an instrument for those stage performances and campfire fun. As mentioned before, it would be cool to have people instruct others in what they are good at. Maybe if you have some real talent there you could invite the town for a show, not sure if that would just be more logistical difficulties.
I have some more things for you to consider, like whether or not you want to keep police officers off your land. I am not sure how to advise you on this.
