The following links can be useful as you use LaTeX and explore more of its applications:
TeX StackExchange (https://tex.stackexchange.com/): question and answer site for using TeX, LaTeX, etc. You can search past questions using the bar at the top, or ask your own.
Detexify (http://detexify.kirelabs.org/classify.html): identify commands for symbols by drawing.
Comprehensive TeX Archive Network (https://www.ctan.org/): a network of websites that offer material about TeX.
Learn LaTeX (https://www.learnlatex.org/): set of lessons for getting started with LaTeX. Learn LaTeX differs from this tutorial with more in-depth exploration of formatting, and less focus on math.
Getting to Grips with LaTeX (https://www.andy-roberts.net/writing/latex): another beginner's tutorial, with topics like bibliographies, figures, and tables.