Fellow C++ Developers, how do you know which data types to use in certain situations, and how do you remember these data types for C++

I am learning C++ from scratch, and I'm finding difficulty with remembering certain fundamental data types. I understand that looking things up is the way to go, but a lot of times, I'm confused as to what I should even look up. This is especially true for certain data types like int_fast64 which I did not even know about.

My question to C++ developers, especially those with work experience, is how do you know which data types to use in certain situations. Is it something that you fine-tune over time through practice? Or do you keep a reference to see all the possible data types.

If this question is not relevant to this website, please let me know. Thanks!