Take a look at the NK_baseline.mod in the Dynare examples folder. The header and footer should not be altered. It says where you can enter your own equations.
However, if you are doing nothing fancy like calling a solver, go for a steady_state_model block. It will automatically create a steady state file. Take a look at Pfeifer(2013): "A Guide to Specifying Observation Equations for the Estimation of DSGE Models"
https://sites.google.com/site/pfeiferecon/Pfeifer_2013_Observation_Equations.pdf for examples.