I have a used Nikon D750 with a Nikon AF-S Nikkor 24-120mm 1.2G ED N lens. I would like to take pictures of flowers, being real close and getting all the detail. I find that I can not get close enough with what I have. I have to be too far away to get the camera to focus on the subject. Any suggestions on a good macro lens? I have a 50mm lens I just purchased and it will focus on the floor but not the subject in my lap. what am I doing wrong? There has to be something that I am missing. All help and comments are appreciated.

thank you for all your comments!

I saw this add for mpb for selling your older camera gear. You can also buy used equipment from them. Has anyone used them before? I read the reviews online and of course they are all positive. I bought a used Nikon D750 at Hunts camera for Christmas and I no longer need my two Nikon D80s and DX lenses that I have for them.