segregation of duty(SOD), Sensitive transaction, and SOD conflicts

Dear all,

I would like to know how to check SOD, sensitive transactions and SOD conflict?

As I have no information about these things and I am new on IT governance role, our company do not have SAP GRC.
We are working on SAP ECC 7, EHP 7.0. I do not have any idea how should I start work on SOD and SOD conflicts, I dont want to loose my job, I need help from every way how to perform this duty effeiciently.

This is new position in our company.

please help!!