I’m trying to have different column styles on the same page. I want to have a single column on the first half, a line break, and then two columns, each with bullet points on the second half of the same page.
Ciao, you can do so:
Press Enter till half page, and select one or two lines before the last. Then:Format > Columns > Settings ….
Then, in each column:
Format > Bullets and Numbering ….
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The number of columns is a property of the page style. So, basically, you cannot “locally” change it. To do that, you must specifically request a property “exception” through a manual break to a section.
Start your page as usual with the single column default. At the location where you want to switch to 2-column layout, add a section with Insert → Section... and select the number of columns.
Revert to single-column with another Insert → Section... after it.
If you want to anchor the sections to some fixed page position (as I understand your question), you may need to add a page break attribute to the first paragraph of the single-column section. Do that through style definition/modification rather than with manual direct formatting.
I would not recommend to give the sections fixed sizes because this would involve storing one of them (preferentially the 2-column one) in a fixed-size frame and you’ll bump into problems with positionning, text flow, wrapping, … The page break attribute of the first paragraph should do nicely the trick.
Concerning the bullet point issue, it is independent from the 1/2-column sections. Just choose an adequate style for your paragraphs. By default, you have Bullet x (x is 1 to 5).
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Columns are property of either page style, or a section. (Just to make clear that sections aren’t a kind of “cheating”, which impression I got from reading your preamble.)
Selecting text and using Format → Columns (as in @charlie.it’s answer) implicitly inserts required section, so no need to worry about that.
@mikekaganski: not knowing the skill level of the requester, I tried to make things simple. Of course, as is implicit in my answer the column property is present in both page style and section. Mastering all subtleties in LO is not immediate for a newbee. And even with experience, you still need to experiment.
What is not obvious is whether the document is multi-page. For single-page, @charlie.it solution is enough, though I disapprove usage of Enter for vertical spacing instead of style.