Welcome to the forum. 
It’s up to you really. If you think you’re ready for Elite difficulty then you can move on to that. If you find it too hard you can always go back to Normal and do the Forgotten Gods expansion.
One thing you could do is leap into the start of Forgotten Gods and do the first couple of quests there which will allow you to ally with one of the Witch Gods factions and get a movement rune if you’re interested in those.
Then you can go back to Elite difficulty or carry on with the FG content.