Wild Space?

That takes some digging since this is apparently common knowledge, but one of the basic primers (almost certainly for kids) has the answer - Wild Space is what happens when no one owns an entire region! Rather than just exploding everywhere, you get large scale random magical effects, with the local coherency of things like cause and effect decreasing over time. There's a picture of a reclaimed bit of Wild Space with trees made of bones and soil made of jelly. Sometimes monsters wander out of Wild Space.

Gosh! Are new planets generally wild-type? Also how does space travel work.

Newly discovered planets usually are, though some have an uncontacted population that owns it and keeps it stable (sometimes people who left to go colonize and dropped out of contact, but rarely also the chaos spontaneously makes people who can claim things).

Esulri doesn't seem to own any books more complicated than 'aimed at children' about space travel, but generally only the personal ships of Overlords run on magic; everything else runs on technology, using either wormholes (probably made by ancient magic; they're pretty much giant portals across huge distances) or hyperspace (slower than wormholes but doable with technology; the book describes it as 'like folded space' with a sense that's actually a horrible oversimplification) to go really far distances, like between stars. Wormholes are a lot cheaper, safer, and faster, since proper lightspeed ships are expensive and get lost in hyperspace a lot.

Whoa, spontaneously made people. Are they humans or are they weird magic people?

How physically large are non-magical spaceships. What kind of passenger capacity are they looking at. How do they find where it would be a good idea to go.

Mostly apparently weird magic people, but you're more likely to get humans even if you're less likely to get people at all in marginal Wild Space (which is close to owned areas, especially owned populated areas).

Non-magical spaceships come in a lot of different capacities but several of the ones mentioned have minimum crew in the hundreds. There's not really statistics but there seems to be a sense you could fit a city in the biggest spaceships, though ones you're sending to lightspeed instead of through wormholes usually are very small, a few dozen passengers at most. Lightspeed ships need to be carrying someone capable of interfacing with the magic system, for some reason, but sublight ships are usually run by computers.

Usually figuring out where to go happens through some combination of telescopes (which can tell you what something very far was like many years ago), small lightspeed scouting ships with minimal crew, and sometimes Overlords with far-viewing powers taking an active role in exploration.

Well, that makes obtaining a spaceship or several and hauling them to his world to be loaded up with evacuees for in-world transit seem less plausible.

Wow he's been reading for a really long time and he's hungry. "Esulri?"

"Yeah?" Esulri calls out, coming back into view.

"How should I go about getting something to eat?"

"I have food."

"Where is it and does it need preparation?"

"Kitchen. Some does, some doesn't." He gestures for Cor to follow him into another room.

Cor will follow Esuri's lead on food. "Unfortunately all my cooking skills are from another universe's magic system and also heavily rationed right now."

"Yeah. That makes sense. Don't use magic to cook, here..."

He makes simple foods - assembles a sandwich from existing cut bread and cheese and then some slightly wilted lettuce and tomatoes and condiments. Drinks are just existing bottles that were in the fridge. (He's somewhat too tired to actually cook.) His pantry seems pretty bare, overall, though.

Sandwiches are fine, and anyway there's approximately a famine going on at home. Cor does not complain.

"Find what you wanted in the books?"

"Much of it, yeah. It doesn't seem like it will make sense given the kind of deadline I'm working with to steal a spaceship to put evacuees or even scouts on, though."

"Yeah... Maybe a big station? That might be hard to move. But they get pretty huge, even if they can't go anywhere fast."

"Do they ever land? I have to be able to make marks on or around whatever I want to bring along and if they're floating in the sky at all times I can't."

"...The big ones don't usually I don't think."

"Then it seems like it might be difficult to paint one." Sigh.

"I also dunno if there's any less assholeish Overlords who can help... Though that'd be maybe high impact, from our side."

"It seems like they have a lot of power to throw around, just, uh, not in a consistently helpful way."

"Yeah."

"It'd be better than waiting for everybody on my planet to get sucked into disappearance but somebody else might find a better universe so I don't want to commit to it till I hear how they're getting on."