NOTE-TAKING APPS
Having a digital notes feature is similar to having a paper notebook with tabs. Using it in an electronic way has its advantages, as you can save website addresses (URL) easily, screen capture images & displays, forward information with a click and type notes 'on the go' from your phone.

There are multiple note-taking apps you can use.
Popular ones are:

Microsoft OneNote - a free note-taking app
Here is the link to their video training page.
https://support.microsoft.com/en-us/office/onenote-video-training- 1c983b65-42f6-42c1-ab61-235aae5d0115

Evernote - the ultimate digital notebook
Here is the link to their website info.
https://evernote.com/why-evernote

Apple Notes - for Apple users
Here is the link for 'iCloud User Guide - use Notes'.
https://support.apple.com/en-au/guide/icloud/mm6704cac5/icloud

Google Keep - for Google power users
Here is the link for 'How to use Google Keep'.
https://support.google.com/keep/answer/2888240? hl=en&co=GENIE.Platform%3D

Android Notion - for collaboration
Here is the link to their website info.
https://www.notion.so/product

Obsidian - for power note-takers 
Here is the link to their website info. The data sits in a local drive, offline. 
https://obsidian.md/