Notes Rate of Return

[Andrew Neaville]

I am new to note investing, and I am wanting to start buying notes. How do you find the percent return on your money? I am doing it this way, but I am not sure if it is correct. I am using a financial calculator. These numbers are just made up. 

1) The purchase price of the note is $20,000 (plug this value in to the PV key)

2) The number of payments remaining is 204 (plug this value in to the N key)

3) The total monthly payment is $584 (plug this in to the pmt key) (Do I use the total monthly payment or just the principal and interest payment??????)

4) Solve for the I/YR (this would yield a 34.94% return)

Also, if anybody would be willing to message me and allow me to ask questions, I would greatly appreciate it!