If you need to learn about LaTeX, then Overleaf is a good environment to build your skills. Overleaf is a popular online editing tool, that allows you to create LaTeX documents directly in your web browser.
Once you have set up an account (sign up for a free account) you have a choice of self-paced study resources to help you progress. Choose the one that suits your own learning style.
Videos: Introducing LaTeX using Overleaf
A series of 22 short videos. Total playing time under 1 hour.
Visit the YouTube channel and watch videos
About Overleaf
Interactive Introduction to LaTeX
An online course with slides to read and interactive exercises for you to complete online.
Visit the interactive course
How-To Guides
A knowledgebase containing articles to read, on how to solve some of the problems that LaTeX users may face.
Visit the knowledgebase