Hi Becky if it makes you feel any better I did exactly the same! spread horse manure on my beds before i realised it was better to let it rot 1st.
I got some great tips for managing manure (see “dodgy manure” thread) and the stuff I stacked (and have turned twice) looks like it is ready. Certainly there is no smell from it. I think if you “compost” the manure now it may well be ready for spring.
Even if it isn’t quite there you can be happily smug that you have a pile of good stuff waiting for you for next autumn.
Get the cardboard down and at least the weeds will be dying
And welcome! you’ll be surprised by how many novices there are here and also how helpful all the experts are.
Good luck!
