If you know the number of a resolution, e.g. General Assembly resolution 62/24, you can locate it by accessing the Digital Library. To search for the resolution, you will need to build a UN document symbol:
You can search for Resolutions in the Digital Library by using words that appear in the Title, e.g. "Multilingualism". You will be able to access all documents pertaining to your chosen Title and select a particular Resolution from the list.
Consult the following section of the UN Documentation Research Guide: