Definitely doable. One 12-hour shift/week isn't bad and you can work on your basic skills. It will also help get your foot in the door when you graduate from your nursing program and are looking for a job!
When I worked as a PCNA, I did one 12-hour night shift/week, usually only a Friday or Saturday night. If you're not used to working nights it will take a few shifts to adjust working that schedule but you'll get used to it. It wouldn't be a bad idea to bring some school work or studying material for when you have downtime. Most people think that all we do is sit around on nights, but that isn't always true
Things that help me:
* get some black-out curtains. If you can't get those, get an eye mask. Dark environment helps promote sleep.
* Try to stay up as late as possible the night before your shift and then go to bed in the morning. If you can't do that, go to bed, wake up really early and then take a nap during the late morning/early afternoon so that you will feel refreshed for your night at work. I sleep in the morning until around 1500-1600.
* If you drink coffee, drink it! But remember to stay hydrated, as well. I usually drink some coffee when I wake up and then drink a little while I'm at work. I cut off my caffeine supply by around 0000 so that I will be able to go to sleep in the morning.
* If you're feeling tired at work, go take a walk around the unit. Better to do that than to sit there and feel even more tired.
* Tell your friends/family/SO of when you will be sleeping. Remember, their 1pm is your 1am! I turn my phone off but all of my friends and family are very understanding of my sleeping schedule. My husband is also very quiet when he's home.
* Be sure to eat healthy. Weight gain happens when you're working nights!
* When I'm done working my 3 nights in a row, I go to bed in the morning (usually between 0800-0830, depending on when I get off from work) and then try to wake up around 1 or 2pm. If I sleep all day, I will be up all night.