We get sooooo many of these! I usually go through the case study with a highlighter and highlight all the relavant bits and symptoms, disregarding anything that's a red herring (they love to throw those in there). You'll become a hawk-eye before too long...look for words like "paralysis, labored breathing, pressure injury, poor skin turgor etc" and highlight those.
Then write them all into a list and start giving them numbers for priority. Remember that your first need is OXYGEN...so anything that impairs that (eg: breathing, airways, circulation etc) will be your first port of call. If there is nothing like that, think BRAIN...any kind of weird thing that could be caused by a problem in the brain, or after surgery where they might have sewn a nerve etc. When you have your number one priority, make that your first "assessment" and figure out what kind of assessment to do. Eg: If your patient comes out of surgery and is suddenly unable to move her lower body, then you'll do a neuro exam. If your patient is a long-term smoker who is coughing up sputum, then a respiratory assessment. If she's got a poor colour, maybe a cardio.
Then go down your list and figure out all the other priorities in order. You will begin to make natural connections that you hardly have to think about. If there is immobility, think "pressure injury". If there is poor skin turgor or any kind, assess for dehydration or over-hydration. Bloating, flatus, diarroeah, constipation - elimination needs must be met.
Further down the list, look at stuff that your pt has in situ - IDC, IVT, NGT etc...all that will need to be cared for. And of course vitals are always on there - how often will depend on what your priorities are and what has been compromised.
After that it is "comfort care"...washing, making beds, keeping the area accessible and tidy, ensuring social/emotional needs are addressed etc.
Then you can just put it all together in a document and hand in! And better still, if you've got it on your computer it can all be cut and pasted into a careplan in order of priority. Then you'll just have to fill in the blanks for goals, rationales etc.