It depends on the class and the level. I've worked classes where they never really see a beam for some time. They have no skills to transfer there and it's hard to keep moving. We can get more done from a gymnastics standpoint elsewhere, and eventually the transition of movement to the balance beam will go much faster and more confidently. I'll usually put them up there at some point to see how they're walking and how they react, but I don't do beam lines on high beams or anything like that.
Bars, yeah I feel the need to have bars in there pretty much every time because floor skills don't really transfer there and they need to build the strength and coordination, work on the correct finagers, hand and arm positions. Some gyms have a beautiful set up for bars, others not so much, but with beginners if you have an extra p-bar set and you make them uneven, you can have them do jump up, chin hang, jump up climb grab the high one, turn around, assisted chin ups with legs on lower, pullover, single leg cut through, casts, cast off, all the beginner stuff. Until they're doing front or back hip circles and underswings, that's worked fine in my experience.
Edit: if absolutely no bar set ups were available, I would use rings for tuck hang (foam block), L hang, skin the cat, bent arm hold (rings by ears), pull up from L hold, etc. If no rings were available, then a floor bar over blocks (have kids sit on ends for stability) for basics like feet to bar hold, skin the cat, L hang, chin hold, etc. If NONE of this is available then we have a bit of an equipment problem, I don't even know.
Vaulting...always an interesting task and I work some very early vaulting movements into my floor rotation for beginners. Ex, we have a half sphere mat for wobbling with preschoolers, I turned it over on it's flat side, put a carpet in front of it, and a panel mat behind that, the kids were instructed to stand on the panel, kick their good leg up, jump to two feet on the carpet (one foot to two feet), reach for the dome and squat on. Probably about half could do this after some instruction. The rest sort of did when I physically put them through it but it was touch and go. If I have some extra time I put one of the small springboards down and see if any of them can do "one foot to two feet" i.e. hurdle but it's the rare class kid who can get that in one day in my experience. After several turns, some of them will get it 50% of the time.
Until they understand that, there's not a lot I can do with them on the actual vault and the jumping down off something higher to the floor is much easier to teach the one foot to two feet action, and easy to put in my floor stations. I'm sure some people interpret that as never taking them to vault, or not doing enough beam, but I have lines down in my floor station too and put some beam movements in.
The bottom line is a lot of my beginning classes are designed to improve strength, flexibility, and coordination, and not necessarily to quickly teach "real" gymnastics. There are ways to do that, but eventually you'll hit a wall where they can't move on to the next sequence of movements. Also, if they are under a certain age, the class rotations and activities need to keep in mind attention span and "fun" factor, everything shouldn't be so serious in my opinion. I want to see them moving and improving the quality of their movement. It is not that unusual that this doesn't mesh with what people envisioned their child learning right off the bat or what is "real" gymnastics. Ultimately when they are a little older, stronger, more flexible, and understand basic movement principles, you can teach them more real gymnastics quickly, with less injuries and accidents, and better.