I have an assignment to develop a POS system which also includes some features of employee management and also customer management. The system need to be able to produce chart and reports as well.

I primarily have experience working with winform but many have suggested that I go for WPF because winform is not really used much. Should i stick to winform or should I try WPF?

We also have the option to develop this system as a web app however i only have a limited experience with php. Should i use what I know and go for winform or should i adapt and try out wpf or php?

Sorry if any grammatical errors as english is not my first language. Also of the requirements are unclear please do let me know