What should I know before troubleshooting my sewage pump? Will sewage come out when I try to get into the basin?

Test for power at the outlet the pump is plugged into. If you have power to the pump and its not pumping then you open the seal. Sewer gas may come out but not raw sewage. Could be a bad float or a burn out pump motor.

what should i know before troubleshooting my sewage pump? will sewage come out when i try to get into the basin?

Bob's giving you some great places to start checking but my question is What's the complaint? What is it you wish to check? What is it doing or not doing? Let us know, Tom