I will know some of the folks you'll meet on Saturday, through Ravelry mainly, and I can assure you that if you are helpful and clearly wanting to learn how to present what spinners want to buy, you will be welcomed with open arms and given any amount of help and advice

It would be a good plan, if you haven't already, to read up the excellent leaflets Sarah Wroot wrote; you can download them from the Yarnmaker website
hereI have some Romney fleece, and although it's not the softest of the longwools that I have got, it just makes you want to spin it. So open it out as Fleecewife suggests, and let people handle it

I would climb over people to get some Corriedale fleece to try... I think I may PM one of the Hampshire Ravellers; if she's coming to Woolfest again this year she can buy one of your Corriedale fleeces for me and bring it up at the end of June!

Be prepared that not all of your fleece will be appealing to handspinners, even though they are good breeds and should be. There having been no attention paid to fleece for some time, due to its being sold very cheaply, there is now a lot of variation even in breeds that are supposed to have good fleeces for spinning. And other factors affect the fleeces too; the weather, the health of the sheep, the workload (she may have had triplets, in which case she won't have put as much into her fleece as an untapped hogg), how it was clipped, how it was wrapped, how it was stored...

some or even all of your fleece will be nice and you will learn a lot and make some friends - and hopefully start to build a customer base for the future.