Welcome to the board from Southern California!!!!
Somewhere on the board is a whole list of those little abbreviations. You can use the search button.
To start with.
BOM Block of the month
DD Darling or dear daughter
DH Dear Husband (or Darn Husband)
PM Private message. You click on their name and then when you get to a profile, click send a private message and you can message someone privately
FMQ Free Motion Quilting
SS Secret Santa
DGS Dear Grand son
etc.............