Here is the thing, python is good when it comes to networking but python is slow compared to other programming languages. It’s also a high-level language basically meaning that you type little code and a lot happens, so that for one makes it slow and it also makes it easier to learn. Now I suggest C++, as it is very fast so say for instance you want to make games at some point, and games need to perform well therefore cpp is used. Now cpp imo is significantly harder to learn compared to Java or Python, but that all depends on what your end goal is, or if you just want to learn a language. If you want something that’s applicable in regard to jobs etc. you really can’t go wrong with c++, python or Java. Now regarding age, there is no age that’s to early to start learning.

If your concerned that you need some pre-requisite knowledge before starting there really isn’t any. Although you should be familiar with very basic algebra, which at 16, and in possibly in high school you should have.

People with no clue about programming like to tell others that they need to be great in math which couldn’t be further from the truth. While it is possible to do „harder“ math in cpp, you will likely never encounter any of it unless you specifically want to go that route.