Hello!
I am starting my last year in high school this year and Machine Learning looks interesting to me.
I know some C++ from what I did in my school, but not much, and I like math.
I am wondering if I can start studying Machine Learning (and if you could give me some resources I would appreciate it), or should I wait until I go to college.
Theoretically Speaking, If you have sufficient Knowledge of Linear Algebra, Calculus and Statistics. Yes.
You can beging testing your knowledge with that:
By the moment I can only recommend you to gain strength in the quantitative disciplines, then, when you go to college, pick one or two courses on the field, (or watch them on youtube) and see if they like you.
You’re never too young to learn about machine learning. There are certainly complex topics in ML but it’s honestly not as bad as you might think. You also don’t need a full course in calc & linear algebra to get started. Here are some places you can start:
This playlist has great explanations of ML topics (I watched a lot of StatQuest for my data science class):
If you want to actually try some coding … scikit-learn is a great python library. It also has comprehensive documentation: scikit-learn: machine learning in Python — scikit-learn 1.0.2 documentation. I’m sure you could also look up some youtube tutorials on it also.
Getting familiar with this content is a good idea if you are interested in ML / want a head start in any Machine Learning / Data Sciences classes you might take in college.
Hope this helps 
It’s never too early for starting, but it’s not the way I’d recommend to you.
I got it after ending my bachelor in computer science and starting my MsC. Why? Because you need to have strong mathematical concepts that you’ll get during your bachelor.
You can do it, but your progression speed will be slower that way.