All right, here are some sections from various places in my Notion space(s). I only blurred some of the roleplaying stuff in the unlikely case my players wander in here by accident (because those would contain spoilers for them):
Life
Things that matter
This page is kinda the “entrypoint” to everything else. I have a bunch of favorites in the sidebar but if I want to go anywhere else: here is the place to go from.
Books
I use this page (a database in Notion speak) to keep track of the books I wanna read, or I’m currently reading. As you can see I got quite the backlog. 
Conferences
Here I keep track of interesting conferences and potential talk submissions. The cool thing about Notion databases is: you can have multiple views on the same DB which allows to focus on various parts of the data at hand.
For example, here is a calendar view of the “Concrete Conferences” DB:
Fitness
This page is where I keep summaries of some of the exercises in my routine. Not for all of them but only for those were I need to regular reminder on how to do proper form. I use the expandable blocks a lot here, as you can see.
Roleplaying
Overview
This page serves the same purpose as the “Things that matter” page above but only for one of the campaigns I’m running. BitD stands for Blades in the Dark which a really great system.
Planning
This is a page aggregating and embedding various DBs for a quick overview of where I’m standing as GM and what will be coming up in the next sessions. I blurred some of the things here to not spoil my players should they ever wander in here.
NPCs (Non Player Characters)
A database of important and secondary NPCs in the campaign and their standing towards the group. While this technically contains more information than the players have it’s not like they couldn’t deduce how some of these people stand to them.
As you can imagine the standing of NPCs towards the group is in constant flux.
Factions
While the NPCs are a single character here we have factions, speak groups and their standing towards the player characters. I’ve chosen the list view here to show a different perspective on the same data (here they’re ordered by strength). But of course I also have a perspective similar to the one of the NPCs.
Especially for the roleplaying stuff I use the DBs and interlinking between them quite heavily. For example I have a “Heist” DB which also contains references to affected NPCs and Factions. This is great to keep the big picture in mind without having to shuffle a lot of paper around.