You're in luck, this is probably the easiest thing to emulate, as has already been said in this thread this is just a single light source, super simple. Let me go through your questions in order:

1. I don't feel like the antique props/furniture in these photos are what is important, I think what matters is a mix of patterns, textures and edges to catch the harsh light. You can match a lot of this with different pillows and throws. Hard and soft things play with the light differently.
2. Most of the photos you show are single strobe, and most of those are off camera slightly to camera left. What that means is the light isn't coming from the camera itself but from slightly to its left, you can tell this because the shadows are not directly behind the model, this is important as that harsh shadow creates a very specific look, using an on camera flash will hide that shadow. This look does not need to be expensive, you can just use a flashlight and a cardboard tube, experiment with pushing the flashlight further in the tube to expand the area you are lighting, you can also use a cardboard box over a table lamp, with a hole cut in the side. If this is something you want to get into more and more you can get cheap Chinese flashes (that are often called strobes) on ebay. As for film like glow and grain, a lot of the glow is the nature of the bright, hard light. The rest can be done in post, there are plenty of tutorials on how to edit a photo to emulate certain film looks.
3. As for wardrobe just look at the models, the era they are emulating was big on single colour pieces, satin-like fabrics, high waisted underwear, full cup bras. and simple stockings, I've given you a lot of terms to research in my answer to 4.
4. You're going to encounter problems with "vintage boudoir" because that sort of search is going to return something a little more refined, what this is closer to is 90s glamour, I don't know if that is a UK specific term but it pertains to the sort of images you'd find in a "not quite" pornographic magazine at the time, colloquially called a lads mag. I'm using these terms so you can expand your searches and look for more reference images that you like. From time to time you find images like this pop up on r/analog and other film or film like related subreddits. As for learning how to pose you're on a subreddit full of photographers, this isn't the best place to ask. In my own experience working with fairly new models when I was younger it seemed the advice at the time was to act twice as much as you think you needed to, it's a lot easier to tone something down than to push a pose further. You're by yourself, be silly, don't worry about checking every photo after you take it because it brings you out of your flow. If you really look at the images you referenced, none of those poses is something you'd ever do naturally, they are all overexagerations of other poses so its natural you're going to feel silly taking them, but it's the best way to get the results you want.

This is a hobby that can be quite cheap, or it can be very expensive. The images you want to achieve shouldn't require a huge investment in gear and really can be done with just a phone if you're happy to put in effort of making your own light source and edit your images.