Transfer files on USB to MacBook Air

Look at these links:

the first link is about how to reformat a usb-stick on your Mac.

The second link can help you to decide which format you want ( do you want to use the device on Mac only or also on a Windows PC e.g.)

https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac

https://support.apple.com/guide/disk-utility/file-system-formats-available-in-disk-utility-dsku19ed921c/20.0/mac/11.0

Need a little more info here.

As it stands there's no indication as to what the problem is.

For example, you don't say where the files came from - another Mac? a PC? Some random dude you met on the street?

Then you don't say what the specific trouble is - for example, it isn't clear whether you're asking how to connect the drive (most USB drives use USB-A ports, whereas modern MacBooks have USB-C ports, so you may need an adapter.

Or maybe you have the adapter and the drive is physically connected, but you're not seeing the drive on your computer?

Is there any error or status message that appears? Usually the OS will report if you attach a disk that's unreadable, so knowing that would help, too.

Formatting is probably the least likely issue. Unless it's formatted with some non-standard format, the Mac should be able to read it if it's using any of the common Mac or Windows (or even UNIX) filesystems.

Select the files, right click and choose copy. On your Mac, paste the files where you want them

Be aware of the fact that reformatting erases everything what’s on your usb drive