Here are some references for interesting topics which go beyond your usual CEGEP math courses, which you could use for some vacation reading/watching... Most of these are free and available online, some others are actual textbooks, which you should be able to find in our  or a public  library.
Even if the topic titles don't mean anything to you (yet), or if they don't sound that interesting, I highly recommend you just watch some of the videos, I think you'll be pleasantly surprised. Also, don't be discouraged if you don't understand everything shown  the goal should be firstly to just get a rough overview of all the different kinds of "Math" which are out there, and see if you find a topic interesting.
Have fun (and let me know if you have questions or want even more recommendations)!
Gabriel Indurskis
Fractals

Introduction to Fractals: Fractals and how to build a Sierpinski Tetrahedron (Henry Segerman)

Fun YouTube videos:

The following website, make your way through the listed topics one by one as you like (this was coedited by the late Benoît Mandelbrot, who is usually credited with "inventing" mathematical fractals):
http://users.math.yale.edu/public_html/People/frame/Fractals/

"The Fractal Geometry of Nature" by Benoît B. Mandelbrot (1982)
Probability and Statistics

Videos:

Download this free, opensource textbook, and read Chapters 1 and 2 (or more if you like!): https://www.openintro.org/stat/textbook.php?stat_book=os
Knot Theory
Knot Theory is a subfield of Topology which is also related to Graph Theory.

Videos (all of these are on the same playlist of fantastic videos about knots, but I in particular recommend the following):

Video: Introduction to Knots & Invariants (Andrews University)
Topology

Videos:
 Topology Riddles (Kelsey HoustonEdwards, on PBS Infinite Series)
 Too Many Triangles (Henry Segerman, on Numberphile)
 The Bridges of Königsberg (Cliff Stoll, on Numberphile)
 Sewing and cutting Klein bottles (Cliff Stoll, on Numberphile)
 Doodling in Math Class: Snakes & Graphs (Vihart)
 Network Mathematics and Rival Factions (PBS Infinite Series): using graph/network theory to analyze friendship/rivalry relationships (with some references [and mild spoilers] for Game of Thrones)

"Flatland: A Romance of Many Dimensions", by Edwin A. Abbott (satirical novella, first published in 1884, now available for free): Note that women are described in a nonfavorable way, but this is in fact meant as a social critique of society. Please read the section about this on this Wikipedia page before misunderstanding this aspect of the book.

"The Shape of Space" by Jeffrey Weeks: a great introduction into the topology of 3dimensional spaces

also, this related (old, but great) 8min video about The Shape of Space
 also related, this 3min video by PhDcomics about The Shape of Space from a physics point of view
Complex Numbers, Quaternions, and more

Euler's Formula with Introductory Group Theory (3Blue1Brown)

Möbius Transformations Revealed (Douglas Arnold and Jonathan Rogness)

Visualizing Quaternions: An explorabale video series by Grant Sanderson (3Blue1Brown) and Ben Eater
Useful free/opensource Mathematics Websites/Software
 CoCalc (Collaborative Calculation in the Cloud): This includes the computer algebra system "Sage", amongst many other things. Highly recommended. Watch the short video on the main page for an introduction.
 Desmos (easy to use online graphing calculator)
 Geogebra (great for geometric constructions)
Mathematical Typesetting (LaTeX)
 Introduction to LaTeX (GVSUmath)
 Intro to writing with LaTeX on CoCalc.com (previously called SageMathCloud) (Vincent King)
Programming
 Python from Scratch: Online introduction to Python by the University of Waterloo
 Pythonchallenge.com: An online programming riddle (can be done with other programming languages)
 CodeCombat.com: Learn programming by playing a game
 Code Academy: More serious (but great) online programming courses
General
 What's the fastest way to alphabetize your bookshelf? (Chand John)
 The mathematical secrets of Pascal’s triangle (Wajdi Mohamed Ratemi)
 Floating Point Numbers and the limitations of computers (Computerphile)

Math and Movies  Animation at Pixar (Numberphile): amongst other topics discusses Bspline surfaces

Any of the videos on these great YouTube channels: