If you are level 73, you're currently on track for level 100.
Your quests have contributed for 22.5 levels if you're on the standard path or 45 levels if you're on the extended path.
Objective for next week: Level 81
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
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 Aretuza's Cosmetics. Most of those contracts can be completed after the end of the Journey.
Some contracts you can do right now:
If you're on the extended path and on track, you can complete all contracts tied to cosmetics from now (Play 40 on each type of board and play 10 games with themes from Aretuza's Journey). You can now focus on reaching level 100 and completing all your weekly quests.