I want to create gay bara games.  I'm a programmer in several mainstream languages.  Where do I begin to learn to develop these games?

It depends on what kind of games you want to make. There's a reason why game genres are defined by gameplay, not story.

Depends. First, you should take a look on some games that you like and see what were the dev tools. For example, Robin morningwood was done on unity. Ergi is Daz+Ren'py, Demitransference was made with Twine.

Hi. My friend and I also want to develop a game and all of us have no experiences on game developing, knowing only some mainstream programming languages. We decided to start from zero with c++ based only on OpenGL. For experiments or prototyping we use JavaScript or Python to make a fast demo. Hope this helps. Happy developing!