Hi Everyone. What care plan can I use for Arthritis, Diabetic, and High blood pressure?

Her facility and/or her provider should provide her care plan.

this sounds like an assignment for a class.
If so I think you need to do your own work to comprehend what needs to be done.
if this is not accurate forgive me. And if this person is living in a Nursing Home (aka Skilled Nursing facility) the staff there should be making the care plan.

Your profile says your Grandmother is living in a nursing home. I don't see why you would be involved in creating a care plan? This is usually done by the RN that is in charge of her care. Giving them information to help them set up a Care plan yes, but you setting up a care plan on how you think she should be cared for, I have never heard of this.

Your Grand is a resident not a patient. The NH is now her home and legal address. She is one of many that the aides, LPNs and RNs care for. There is no one on one per se. There are protocols that are followed. Certain things get done at certain times so everything flows easy for every one. There's routine. Showers are given maybe 3x a week. You really can't dictate how people do their jobs and when certain things, you feel, should be done.

We as Caregivers have a hard time adjusting to having placed a LO into someone elses hands. Our LOs will never get the attention that we would have given. Clothes will be lost. You may find Grand in an outfit that is not hers. My Mom had nine outfits that I matched up and put on one hanger so she "would" match. Otherwise the aides grabbed whatever. And her hair! Was never brushed correctly so I carried a brush and hairspray around with me. There was an OP asking why wouldn't the aide put his wifes jewelry on her. Because wife is not the only person they have to get up, dressed, teeth brushed and hair combed by 8 am in the morning. My Mom was well cared for. My daughter said to not worry over the little stuff. She worked rehab/nh for 20 years.

Your question is really too vague, other than "psychological problems from her retired Job" there is no reason this person couldn't be an incredibly capable independent senior. The best way to detail a care plan is to list the ways the person actually needs care...

https://www.agingcare.com/articles/activities-of-daily-living-why-this-measure-matters-186853.htm

https://www.agingcare.com/articles/instrumental-activities-of-daily-living-defined-427370.htm

https://www.agingcare.com/articles/how-to-create-a-care-plan-195526.htm