I remember my first care plan. It was the first time I was frustrated enough to cry. Take a deep breath and look at it logically. The most important things are your A,B,C's. Airway, breathing, and circulation. It doesn't mean too much if you have a heart that is beating and no oxygen entering the body. So, why is your patient on oxygen? Is it because she has an underlying condition? Possible pneumonia? Look at the NANDA nursing diagnosis. Here you have a patient who is in need of O2, isn't able to move freely, has dementia, has a PEG, and is incontinent. If someone isn't able to move you should always be concerned about oxygenation, perfussion, breakdown. With what you have said about your patient you should be able to come up with a care plan to knock your instructors socks off. There's not many of the NANDA's which wouldn't fit it. Just remember to support your nursing Diagnosis with data such as meds, labs, assessment findings ( there should be a place for every one of these). You can get a careplan book but beware of depending on it. You need to process what's going on with your patient and learn how to make a care plan specific. It will all come in time, and soon you will be looking back at your first care plan and laughing. Good luck.