Why can I not access all of the features in Calc?

I want to print the grid lines, but whenever I’m in “print preview” mode I am unable to select the option of showing the grid lines. Everything is acting like I need to pay for a full version of the entire LibreOffice software. Do I? Or, is there simply something I’m missing?

LibreOffice isn’t nagware. The free version is the full version.

That’s great to know! Since that’s the case, how do I get the gridlines to print?

Edit: Never mind! My question was answered. Thank you!

I would like to mention that there are a few useful third-party tools you can install as extensions. I never found one not being free. Anyway you may create a kind of a version “more than full” using extensions.

How to print the Cell-Grid with Calc spreadsheets?

You need to set this for the page style of the sheet.
Menu > Format > Page > tab Sheet
In the Print section enable Grid.

Got it! Thank you so so much!