If you are level 17 (+12/24), you're currently on track for level 100.
Your quests have contributed for 5 levels if you're on the standard path or 10 levels if you're on the extended path.
Objective for next week: Level 25 (+18/24)
Being on the track is just an "average" value for players starting the Journey on the first day of the Journey and playing regularly. You can be ahead or late compared to the value, this is just to give you an estimation on where you should be to finish the Journey on time without any rush.
You can use
A new batch of quests is now available as well as a new part of Yennefer's story.
No reward above level 100?
After level 100, you get 2 reward points per level, but you can get a lot of extra reward points by completing some contracts tied to Yennefer's Cosmetics. Those contracts can be completed after the end of the Journey.
Source: https://www.reddit.com/r/gwent/comments/lqdwmo/yennefers_journey_week_3_youre_on_track_if_you/