How to Engage FMC?

So I have programmed and activated the FMC.  But how do I engage the FMC so the aircraft starts to follow the programmed flight plan?

I have tried engaging the NAV but not sure what the actual steps are, and the manual does a good job describing the programming of the flight plan, but I didn't see when you activate it what you have to do as far as the autopilot to engage the FMC.

Thanks!

There is not RNV on my EFIS panel. Is there an alternative,thanks

Thanks