What's faster to learn in C++ a GUI library or TUI library?

I'm learning C++, I know several other languages and have some experience with C and have read a fair share of x86-64 assembly.

I want to create a simple program with some simple graphics (e.g. visualizing 2D maps very low poly, rendering a chart or visualizing an algorithm such as [1] -- though it doesn't have to be as comprehensive as that).

What's quickest to learn? A GUI lib or TUI lib? I happen to know some OpenGL (and computer graphics in general, having made a 3D OpenGL engine in Java).

I don't want to spend too much time on graphics and rather focus on the internals of managing everything.

[1] https://clementmihailescu.github.io/Pathfinding-Visualizer/