You can find the forms online but most people will advised you to see an attorney in your area. States can have different laws governing poas. It's not very expensive. Make sure to get a broad POA that covers all issues, end of life directives, real estate, finances, medical and nursing home care.
Since your father already has dementia, there will be a legal issue as to whether or not he's cognizant enough to execute legal documents.
If you prepare a DPOA and appoint yourself as his proxy, you're opening a can of worms. And the POA may not even be valid. If you have siblings, they'll have a right to challenge any document you prepare and have your father execute while he has dementia.
If you prepare a DPOA and appoint yourself as his proxy, you're opening a can of worms. And the POA may not even be valid. If you have siblings, they'll have a right to challenge any document you prepare and have your father execute while he has dementia.
Windy's right - you need to see an attorney.