Can you plug in a usb flash drive to any of the apple "lightning to" devices, so I can use to store my projects instead in my iPad?
No. The iPad will not write to a usb flash drive. It will read pictures and movies only.
There are lots of ways of moving files.
A simple and popular way to copy files and share files amoung your devices.
Using iTunes to transfer files:
Files Connect -- The swiss army knife of remote file connect
iExplorer -- " iExplorer's disk mounting features allow you to use your iPhone, iPod or iPad like a USB flash drive."
Windows File server
There are other devices like this.
This dual personality device is both a WebDav device which allows you to transfer files via Wifii between device & iPad and a thumb drive which works with compuers.
Web browser WiFi b/g capable device
Optimized experience for iPhone, iPod touch, and iPad via HTML5
No internet connection required
Compatible with most operating systems that support USB Mass Storage Class (thumb drives)
Firmware update via file drag and drop
this is my first time using an apple product.
The iPad I'd say is focused on simplicity & security. Have fun.
You can use a USB flash drive & the camera connection kit.
Plug the USB flash drive (works the same with an SD card) into your computer & create a new folder titled DCIM. Then put your movie/photo files into the folder. The files must have a filename with exactly 8 characters long (no spaces) plus the file extension (i.e., my-movie.mov; DSCN0164.jpg).
Now plug the flash drive into the iPad using the camera connection kit. Open the Photos app, the movie/photo files should appear & you can import. (You can not export using the camera connection kit.)
Using The iPad Camera Connection Kit
iPad: Using iPad Camera Connector with unsupported USB devices
Secrets of the iPad Camera Connection Kit
There are some wireless external hard drives that can be used with the iPad.
Best iPad External Hard Drive Storage Options
iPad Storage Solutions
SanDisk Connect Wireless Media Drive http://www.sandisk.com/products/wireless/media-drive/
Expand your iPad's storage capacity with HyperDrive
On the road with a camera, an iPad, and a Hyperdrive