I have no interest in this kind of shit and even furry feral genre rarely does it for me.
Unless its like some fantasy monster creatures: pokemon, tentacles, slimes, oversized insects/slugs, mutants and e.t.c. And actually if i consume such a content, the creatures must be male, who they are fucking is not so much, but preferably an human/anthro female/femboy. And this being disgusting is a part of the appeal.
But to the actual topic, I can't share any ideas, but can say that if you don't know how to code, RPG maker is your best bet in creating a game IMO, It is very popular among indie devs and i have used it in the past(RPG maker MV to be precise) It's easy to learn and there are tons of tutorials on how to use it, and you can make a game without writing a single line of code. And if you find that the engine lacks in some feature you want, there probably exists a plugin for it, to alleviate you the burden of coding that feature yourself. If you want to make a full-on VN, Ren'py might be a better choice, but it requires you to know Python to do shit there if I'm not mistaken. But you can make a VN in RPGM too, it's not a big deal, people have done it before.
As for backgrounds, many people dislike AI art, but i believe for things such as backgrounds it can be very useful, since unlike characters, this is something AI can do much better. Maybe you could try using it too.
(Oh, it's a year old dead topic, oops)