I'm in a similar boat. I haven't done any game dev for a few years...
But now that we are living in this social distancing, pandemic world, I decided to use this game jam as an opportunity to teach myself Vulkan. I have a game framework that I've built in C++, but it uses OpenGL and Direct3D. Vulkan seems to be the cool new kid on the block, and it's definitely much more attractive to me given that it is completely cross-platform (even runs on macOS and iOS thanks to MoltenVK). I'm using glfw for windowing and input. Seems like a winning combo.
It's coming along well. Got my first triangle rendered on the screen yesterday. But it is looking like I am going to be scrambling last minute tomorrow to actually build a game for this jam, haha!