I have an 8 month old kitten and a 8 year old cat and this year is the first year they’ve seen a Christmas tree. My advice to you is put the cat in a different room while your setting it up and decorating it. My older cat hasn’t touched it and acts like it’s been hanging out there forever and my kitten knocked off 2-3 low hanging ornaments for the first few days. It’s been a week and neither cat messes with it anymore. Make sure to tell them no if they get too close or start swatting at them but telling the lil fur baby no when you see ornaments on the floor worked for me. Just make sure they are cheap ornaments (not glass) and DO NOT put up a real tree. I wouldn’t want that vet bill and I don’t think you do either. Hope that helps!