Ubuntu USB booting

Hello.
After the last windows 7 update I've found my computer freezing, glitching and generally derping too much to actually use the windows 7 OS anymore. So I've decided to download Ubuntu and install it to a USB and boot straight from that. My question being: Do I need to prep my machine in any way to handle Ubuntu, will booting from USB cause issues with my files on my installed HDD (if so, how highly would you recommend backing up files and folders from safe-mode) and will I have any issues with loading drivers or will Ubuntu automatically copy or download drivers?
I know there's quite a few questions in there. This will be my first time duel-booting so I'm a tad cautious about the whole thing. Some help would be greatly appreciated.

Not really no. There shouldn't be any special prep. However if you are finding that the USB device will not boot, then go ahead and disable windows secure boot if you have that option in the bios.

As for backing up your files..............yeah back them up. Make a back up of the back up.

Back up back up back up back up.