Hmm..... What I am trying to do is change the Copyright info year to 2018. I believe this is done somewhere in the Preferences.
In doing that, will all my images have the copyright info correct?
No, this is incorrect.
Changing copyright information is done with a metadata preset.
Go to the Library module and then look at the top of the Metadata subpanel found in the right hand panel. There you will note a heading called "Preset" which will probably have a setting next it it of "None".
Click on the little arrows to the right and all the metadata presets you have will appear in a list box - it is possible that you have none in which case it will be largely empty. Either way the last entry is this: "Edit Presets". Click on this and the "Edit Metadata Presets" dialog appears.
The copyright section is fourth from the top.
Make sure that the only section that is checked is the IPTC copyright section.
Fill in the relevant fields and then when you want to save the preset go to the top of the dialog box to where is says "Preset" with "Custom" in the box adjacent. Click on the two little arrows to the right and a list box opens showing all your metadata presets. However, what you are interested in is at the bottom (second from the bottom in fact: "Save Current Settings as New Preset". Select this and give the preset a descriptive name such as "Copyright 2018". Click "Create".
Once this is complete the preset is created.
Click "Done" at the bottom of the dialog to return to the Library module.
Applying this metadata preset can be done in a few ways. The key is to select all the images shot in 2018 using either the filter bar or a collection and then selecting the metadata preset by going to the same location at the top of metadata subpanel where we started.
Once selected the preset will be applied to all the images selected (this can be one or as many as you like).
If it is important to write the metadata back to file then do this last.
Tony Jay