I've been using a Bullet Journal for the last 2 years and it's a method that works perfectly for me but there has been times when I forget it at home.
I decided to start using Todoist so I can have it with me on the go (phone app) so I don't forget anything. The first few days it was kind of messy, I didn't understand anything but I'm getting the hang of it.
I usually take notes on my Bullet Journal or on the Notes app on my phone but I started using Evernote after watching the class and I'M LOVING IT.
As for the calender I also use my Bullet Journal and I'm also writting the events on Todoist, didn't really like Google Calender.