Here you can find a few easy tutorials to start editing videos on Reaper.
Keep in mind that these guides assume that you already have a minimal knowledge of video editing and Reaper itself, so if you never opened it before you should do some practice and learn some stuff until you get enough comfortable with it.
Also don't take these tutorials as your only resource for learning, experiment by yourself with all the available presets and functions and look for other guides online.

Chapter 0: Setting up the environment
Chapter 1: Track opacity/zoom/pan
Chapter 2: Effects hierarchy and Text
Chapter 3: Blend modes and masks
Chapter 4: Animating with track envelopes

More chapters haven't been planned yet.

Last updated on 24/01/2021 - "QoL changes to all the chapters"