How to fix a SD memory card?

I just go a nikon D 3400 brand new camera and a sandisk ultra 32 gb brand new as well. I get the card may be damaged insert new card error when i turn on the camera. I tried to pull up the memory card on my laptop and it doesn't come up. What can i do to fix this?

Go to the store

If its new then return it to the store…
otherwise throw it away cause its dead.

Wait. New Camera and new SD card? Did you format the card in-camera? Try that first. IF you format the camera and it STILL shows the ERR notation, the error may be something totally different, not related to the SD card. Look at the camera's Instruction Manual, check the Index and look for Error Notations and look for the offered solutions. Follow the instructions carefully. IF you can't solve the problem, then call or visit the camera shop where you bought the camera and SD card; they'll solve the problem or exchange the SD card for a new one, free of charge.

Take it back for a replacement if new.

You are supposed to format them in the camera itself before using.

Try formatting it on your laptop and then reformatting it in your camera again. If your laptop still can't read it then it is definitely faulty.

You must format the card using the camera's format function.
Never format the card using any other type of device because it'll install a file system that isn't compatible with your camera.
If formatting the card didn't fix the issue, then the either the card or the camera is faulty.

You don't.

At the first sign of trouble, you throw it away and buy a new one.

SD cards have a limit to the number of reads and writes. Then again they are easily abused. Whatever the reason is, they can't be fixed. They can't even be revived. Your only hope is recovering whatever was in it (success vary widely) and to prevent further trouble, you throw the old card away and buy a new one. To prolong the life of your new card, format it regularly.

Isk

Call 911 they'll help you