I bought a ton of these throughout my career since they are the best calculator allowed on the exams but they don't have any graphing capabilities:

https://www.amazon.com/Texas-Instruments-MultiView-Scientific-Calculator/dp/B000PDFQ6K

None of the ones recommended by your professor would be allowed on an exam, but you might need it for the class.

Texas Instruments TI-30XS MultiView Scientific Calculator
https://www.amazon.com/gp/product/B000PDFQ6K/

https://www.youtube.com/results?search_query=TI-30XS+MultiView

I personally use a TI-84 plus CE (which currently runs for ~$120) for engineering and I love the thing, especially with the mathprint formatting. I have some friends who have something more like the TI-30XS, which isn’t a graphing calculator, but also works very well and has everything you need if you aren’t allowed a graphing/programmable calculator in some of your classes.