The transmission fluid type depends on if you have a manual or automatic transmission. Here is a lookup tool that will generate all the compatible fluids after choosing the year for your Honda CRV (I would have posted a more specific solution but I'm not sure which year you have so this is the second best solution):
[link|https://www.searchforparts.com/oil-change/honda/|https://www.searchforparts.com/oil-change/honda/|new_window=true]
As for what to do (leave the engine on off, idling or?) while changing the transmission fluid, the best answer is probably found in the owner's manual. If you lost it, no worries, here is a link where you can find your Honda's owner's manual online:
[link|https://mygarage.honda.com/s/find-honda|https://mygarage.honda.com/s/find-honda|new_window=true]
Another thing you can do is make a voice call to your local Honda dealership for more information. I am sure they will be glad to help.