Keeping steady time happens when you internalize the beat. Practicing with a metronome is the best way to do this. Do it a lot everyday. try playing without the metronome. If you are unsure if you are keeping steady time, go back to th emetronome. Do this until you can tell when you time "feels" steady. Remmber I said steady time. You are not trying to be machine or as rigid as a metronome. That doesn't sound musical. All good musicians will have small changes in the tempo as they play. But not the big speeding up and slowing down that in unmusical. Unless the music calls for it.