Hello! I admit it's not optimized for sharing, this is just a personal doc I've been using.
Basically each row is a separate game, tracked via the Game column. For each game I record the date I played it on and the number of points in my active region, with a new column for each region.
Finished regions I highlighted green, but I copy the values down dozens of rows to keep the Diff calculation happy, which is just a a calculation of (sum of current row points) - (sum of previous row points), which tells me the number of points I earned that game.
The region column headers are just <region name> (points to complete the region) (number of games it took to complete the region).
Finally, the first column is just sectioned into which week of the event it was played on, since the points earned per game increase each week.
Ultimately, all I really care about is points per game ("Diff" column) and how many games it took to complete each region.
Here is a copy I made of the sheet if you want to see the full thing. The bold bit at the top is just a reminder for me to pick certain region choices.
(While we're on that topic - some feedback I have is that while I'd love to pick the region order according to lore or personal preference, when players feel starved for points like in this event, we feel like we need to optimize for point-earning potential rather than for fun. I suspect that's not behavior that your team loves is happening. So as a 95% support player, I avoided picking Noxus first because I knew its Sentinels needed "Dmg to Turrets" and "Phys Dmg to Champs", which I'm not going to get a lot of. There's a saying about designing such that the fun path is also the optimal path, else players will optimize the fun out of a game.)
But I do enjoy the event overall, even if most of the above sounded negative, so (assuming you're part of it) thanks for your work!