You probably should post for the Nano in the Nano forums:
Briefly though, it is common to use JetPack/SDK Manager to install the extra components. Flash and “extras” are really separate steps. You’ll find base installs are more or less just Ubuntu Linux.
See this for listings of JetPack versions (you always use the same JetPack/SDKM version for adding packages as was used to create the root filesystem…a.k.a., “L4T” or “Linux for Tegra”. You may need to go there, log in, and go there again since redirect doesn’t work:
A listing of L4T versions is here (L4T is what goes in the Jetson when it is flashed…or what an image was created from):
You’ll notice the L4T page lists a Nano as compatible with R32.1 through R32.2.1. These in turn are flashed with JetPack/SDKM 4.2 through 4.2.2. JetPack/SDKM are really a front end tool running on a Linux Ubuntu PC, for flash or package additions (it may not be obvious when you start using the tool, but you can uncheck flash and leave only install of tools to the Nano if you are using the correct JetPack/SDKM version). Documents there too go with each release. The L4T and a given CUDA version are meant to go together and normally are not mixed. The image you may have used to add to an SD card was created with this tool. Normally image creation and tool addition are separate steps.