Where do I get the financial and medical forms I will need for my Mom?

Has she been diagnosed with dementia? If so, it's too late to have her do any legal forms. If she just appears to you to have memory/cognitive issues (and believe me - I am not implying that she doesn't have dementia!), do you think an attorney would question her ability to sign documents?

Does she have any documents in place yet?

I hope you can easily get this taken care of.

I myself would go to an attorney. A POA done online may not hold up and there is a lot of trouble then with banks. You need a good, clear, well written POA that your elder is present to do, and proves him/herself competent to do. This means attorney. You also need to understand your duties of Fiduciary duty, that you are responsible for all funds in and out, how to sign checks, how to title accounts, and how to keep records. This is best done with an attorney so you understand your legal duties.

https://eforms.com/power-of-attorney/

If you're referring to medical and durable POA forms, it may be too late for those as you say in your profile that your mom has dementia, and legally she won't be able to designate anyone to be her POA.
Typically a lawyer will do the POA's but since mom is suffering from dementia, you may have to just apply for guardianship through the courts, which is much more costly than a POA.
Best wishes.