Sometimes, as things loosen up, these kinds of sounds appear and they are benign, but it's important that you and the DW (Dear Wife) do a little investigating. You'll need to have the DW raise and lower the trailer with the tongue jack. (the easy part) You on the otherhand will have to get down on the ground and listen for the noises that you mentioned and see where they are coming from and look for any obvious physical or mechanical problems like broken welds or loose U-bolt clamps etc. If you find anything obvious, get it to your dealer ASAP for repair.
Helen & George VE3INB and Max (Bichon Frise)
2006 Silverado 2500HD D/A,
2006 Cruiser CF30SK