Probably obvious, but plan for the worst. Set up camp as early as you can so you can see what you are doing. Try and find a long enough branch to tug at anything above you that looks remotely dead. If in doubt move to another location.
Use a bivvy bag so if the tarp does break loose you can stash it and can still stay dry over night. It gets bloody cold around 3am. Think about your gear staying dry too. Keep the head torch nearby. As said bungees.
I am all for people getting out there, but realistically with little experience (keep an eye on the weather it may change for the better) I would miss a very windy weekend and wait a little till you are happy with your equipment and setup.
Enjoy anyway. Earplugs might help
And there is nothing wrong with trying out your gear in a back garden somewhere, I have done it many a time with new kit and there is no better way to learn than by doing.