Plenty. Most famous one would be Nextcloud. I'm running that for years, and am very satisfied with it. Coming with "core functionality" like file storage, calendar and contacts, it has addons (called "Nextcloud Apps" for quite a lot of use cases – including your todo list (Tasks), a password manager (Passwords, Passman), and many more.
You could use Mongoose Web Server, it's a very lightweight and simple application to host a web page.
Installing and using Mongoose is actually the easy part. The hard part is actually allowing people see your web page over the internet without using a web host that can be crawled by a search engine:
Firewall on your computer:
You would need to create a rule ...
Set your Apache server to serve HTTPS, then create two pages:
3752837652938573294572309457238947532948057.html (containing the information you want to make accessible to your friend)
By default Apache will not tell anyone about 3752837652938573294572309457238947532948057.html. If you don't mention it anywhere on the ...
For development or production?
In any case, see the Big list of http static server one-liners. The gist is from 2013, but the replies and comments are fairly recent.
If you want to set up a webserver with https enabled, you can try PHP- and Docker-based ddev. (Maybe there are easier ways to do this.)
The ddev installer makes creating and correctly ...