There was an error with my Nintendo 3DS camera... so I decided to use its guarantee to change it for a new one... but I had purchased like 25 games from the nintendo eshop... is there a way to transfer all these games to my new 3DS when it arrives?
If you still have the old 3DS, then yes. You can do a system transfer to transfer everything from your old 3DS to the new one.
If and only if you have access to the old system. The games that you download from the eshop are directly tied to the console that you purchase them on. You MUST perform a system transfer to ensure that all of your old eshop data is transfered to your new system. If you do not have access to the old system it will likely be impossile to recover the eshop data from the old device.