I just finished learning what are pretty much the basics of C++ and I'm not sure what to do next. Can anyone give me some simple projects or maybe even a quiz to see where I am and get a better understanding of what I need to do. Thanks!
Here are some of my recommendations for approaching this question (based on personal experience):
Have a solid foundation in it's predecessor: C, which is arguably the most successful programming language of all time, and is what C++ was derived from initially ( although modern C++ has become it's own language ).
C is a simple, compact language, often described as portable assembly, it shouldn't take you long to learn, but mastering it may take you longer than you think.
Have a sufficient understanding of OOP principles, to the degree of knowing when to apply OOP and most importantly, knowing when OOP just doesn't fit the bill. In the words of Stroustrup's "keep simple things simple".
Be practical, it is often said that the best way to master a subject is through practice, this should also apply to learning a computer language. Go try be a mathematician just by reading, I doubt you will get far.
Start small. During your learning process, for each language feature you assimilate write a program, replicating that same feature . Finally, place all the blocks together to build something more complex, just like lego.
That said there are a couple of points worth mentioning:
Online tutorials are just as valuable as books.
Bjarne Stroustrup's , "A tour of C++" is a book that offers a rapid introduction to the language, although it most likely assumes you have prior background in some other OOP language, i.e Java
Once you are satisfied with the above mentioned points, you should start doing research towards a specific area of interest.
For example, if you want to dabble with code injection (windows) you should start by reading the relevant windows API documentation and try find code samples, tutorials to help bootstrap your project.
Another important aspect is having the correct tools for development. So I suggest you acquaint yourself with the standard RE gadgets such as: ollydbg, ida (hexrays), x64dbg, etc...
Finally be patient, understand that learning how to write a meaningful hack takes time, we all started from the bottom, have confidence in yourself / ability and overtime your work will speak for itself.
I'd recommend creating programs you actually plan on using that way you don't lose motivation. I.e. you could make a math application, a formula solver, an application to calculate how much coffee you need, or really anything. And then after you've done that see if you can make it more efficient or add any features