I have created a 1/2 page ( by length) brochure and I want to copy it side by side so that an get 2 per letter sheet
Change the paper size to “landscape” and give the page two columns with the appropriate distance between. Adjust margins and everything to accommodate your “brochure” content in the first column. Insert a hard column break, copy the brochure, and paste it into the second column.
Next time: Prepare your page in advance of creating content.
BTW:
Many printers / drivers offer the option to print two full “portrait” pages on one “landscape” page (or vice versa) scaling the size down by the needed ratio. To draw this option, you have to consider te final size thoroughly when creating the original content.
Writer offers quite flexible configuration of the page layout when printing.
- Open the 
Printdialog (File→Print... Ctrl+P). - Select required printer on 
Generaltab, and in itsProperties, select required paper size (using the printer’s driver UI). - On 
Optionstab of thePrintdialog, check thatUse only paper size from printer preferencesis checked. - On 
Page Layouttab of thePrintdialog, selectPages per sheetas required, and configure options (like order, or more whenCustomis selected inPages per sheet). 
You may also want to explicitly select the order of page numbers if you want some advanced printing, like printing first and last pages together, then second and next-to-last, and so on, like is required when printing for further folding and postprocessing.
This way, you could avoid the need to toss the content over pages. More options (like double-sided printing, and even more flexible multipage layout) can be offered by printer driver itself.