Could someone please tell me if this is mold or not? I think it is but honestly I know nothing about that.

It would be Penicillium or Aspergillus, if it is even mold. They are some of the fastest growing molds (usually within 24 to 48 hours) and require very little moisture for their colonies to develop. I haven't ever seen mold

It's usually not possible for you to remove it from wood, but you are going to want to call someone to get rid of it. You don't know what exactly it is and buying fungicide may help.

Happy(and safe) learning!

--Applepi101 :)

answerbacterium;