5th edition seems to be lacking in needed rules for travel and the like on the Astral Plane, so I've gone diving into old editions to fill in the gaps.

As the game is starting on the Astral Plane, players should have a grasp of some basics, so I'll post them here. along with other facts as they come up.
This message was last edited by the GM at 17:56, Thu 05 Jan 2023.

From 2e rules (Guide to Astral)

Travel to a known color pool:     6+1d6 hours
Travel to an unknown color pool:  6x1d4 hours

Travel to a previously visited Location:         10X1d4 hours
Travel to a described in detail Location:        20X1d6 hours
Travel to a never described or visited Location: 50X1d10 hours

Color Pools:
"Known" color pools is something of an ambiguous area. For a Spelljamming ship I'm willing to make the border between the Astral and a familiar solar system "known". However, a specific place in that system, even just a particular planet, is "unknown". Also, please keep in mind, most color pools can't handle anything as large as a ship, anyhow. Only Border Area color pools.

For travel to an unknown system, the border area color pool is, of course, "unknown".

Obviously, from the times given, travel between solar systems, even to new ones, is relatively fast.

For Astral locations, more is needed:

Previously Visited: obviously you've been there before. This will be something we will have to work out based on backgrounds and other class information. Sages, for instance, are more likely to have visited famous Astral Repositories of Knowledge than cooks.

Described in detail: Again, this is a die roll issue for new players, but Astral Elves and Githyanki with History training have the edge by a wide margin. Others may have information on (at most) one or two areas of particular interest, especially if determined to be new to the Astral (otherwise you'd have visited already)

Never described or visited: Everywhere else. You've heard the name, maybe a brief description that may or may not be accurate, and that's about it. You MAY have one or two such names to start, but probably not. This is also the result of failed History rolls by Astral natives. Sometimes.
This message was last edited by the GM at 00:03, Thu 12 Jan 2023.

A thought occurred:

Astral Space has no biological activity: Characters don't age, food doesn't spoil, even sleep in unnecessary (although rest is needed for spell recovery). Astral and elves and Githyanki need bases in the Prime to raise children (and, presumably, to conceive them).

This means healing in the Astral wouldn't happen, either. All Astral healing would have to be by magic.

On the plus side, poison and disease would need some hefty magic to affect you while Astral, although unknown poisonings and disease exposures could manifest as soon as you return to the Prime.

This makes healing during Short Rests impossible, as well, although there may be other Short Rest benefits based on class, feat, or skill.

I'm not sure if this is House Rule, strict RAW, or overlooked ramification of RAW that seems to crop up in the new SJ rules.

Regardless, these ramifications make survival on the Astral Magical Healing dependent, which is possible, but a pain. SO, Let's do this:

-Poison and disease is held in abeyance until you leave the Astral, then you're hit  and hit hard, especially if you've forgotten. Not impossible, as it could have been YEARS since you were infected or dosed, and you may not even know it.

-Normal healing still happens. After all, a lot of damage in D&D is meant to be a loss of stamina, not holes and bits hacked off. Full healing after a night's rest makes that clear.
This message was last edited by the GM at 23:49, Mon 10 Apr 2023.

Biological functions are suspended while Astral. No trees, forests, domestic animals (beyond the occasional pet), or, really, any source of resources at all. No wood, wool, cotton, etc.

No rural living, either. No point to it.

Oh, there might be the occasional asteroid that's fell through the edge of a system into the astral, which could be mined for a bit of gem or metal, with some luck, but, mostly, those would just host small villages of elf or gith. Bigger cities are probably built on dead gods, some of which might also have mine-able resources.

This is going to mean that nearly everything needs to be imported. Probably on the same ships couples use when they decide to go to the prime to have and raise children.

Spell casters of one stripe or another are probably common. Mending stretches out resources by repairing items, and it's a magical realm, after all.

Crafting is possible, of course, assuming resources can be acquired, but that means prior planning, sometimes months prior for some ingredients, such as herbs for healing potions.

Goods transport is by Spelljammer or Gith Astral Ship, both of which move a group of individuals at one speed, rather than a variety of speeds based on individual Intelligence. Plus they carry cargo.
This message was last edited by the GM at 23:51, Mon 10 Apr 2023.

In previous editions, INT determined movement speed for tactical matters. But 5e is simplified, and tends to cut out the number crunching.

Your fastest speed from Normal, Flying, or Swimming movement rates applies. Burrowing and climbing apply in the proper circumstances, of course, but not in free fall. (And if you have a surface to dig through or climb, it's gravity means you're not in freefall)
This message was last edited by the GM at 01:29, Wed 02 Aug 2023.