I've checked out Jazzo's food guide, but I only have 5231 tech points and haven't bought any techs or fractions yet.

I have been cross training everybody. But only have four workers and the fifth is a nursing mother, this is her second baby. I only have 9 villagers.The honey is gone and the tree is bare.

I just put my four adults into research, as I only have 148 food left.

The children are 3, 6 and 10 and I still have 42 minutes before the baby becomes 2.

I don't have a chief, because I don't have enough workers. I might try for the chief after the new baby is 2, that way I'll still have four workers.

But what do I do if I don't get a chief? I have 1500 tech points to go before I can buy restoration and fix the lift, but even after planting the seeds it's going to take time to grow the trees.

I haven't figured out how to pick more than one mushroom or collectible at a time. I've paused the game, moved all of my kids over to the mushroom, as close as possible, then unpaused the game I still only get one kid picking the mushroom. How do I get multiple pick ups.

In my other games, I put the chief in front of the food bin, and he only made 98 food, which of course didn't last the 24 real hours it takes to have the chief make more food.

Drop him on the food bin.

*** HIGHLIGHT *** SPOILER ***

Note: You need to know the numerical keys for;
Left side, right side, center, etc...
Clicking spacebar pauses & unpauses the game.

Once you see a collectible;
1. Pick up a child and pause the game before dropping him/her on the item.
2. Keep the game paused and pick up a second child
3. Hold the second child over or close to the item.
4. Unpause the game and quickly drop the second child onto or near the collectible.

I hope this helps you!

Before everything else fails read;
The most common causes of villagers being wiped out:

You shouldn't avoid a chief because you need workers; an additional 100 food per day (100, 98, whatever) will be a huge boost when it adds up, from every day since the village's inception, and it may be just the edge you need to last until research is done. Also, your chief will speed up the work of your other villagers, so he will help speed research along when research is being done.

SPOILERS:
(Highlight below to read.)
I put everybody on research to get the tech points needed as soon as possible for:

1. 4,500 to get L1 of the faction;
2. 11,000 to get L2 Science;
3. 50,000 to get L2 of the faction so I can get rid of the sharks.

During this time I'll only use a farmer occasionally if the food stocks are getting particularly low, otherwise the villagers live on mushrooms. I also won't bother with training up builders until after I've got the tech points.
END SPOILERS

EDIT: Perhaps I ought to stress that the above is the way I've found works best for me. Others may well prefer to play differently.

You don't try to grow more fruit trees before dealing with the sharks? I personally find that a single fruit tree and a beehive will absolutely not sustain my villagers long enough to accumulate 65,500 tech points.

Perhaps if you choose nature as your faction you can stretch them out a little more, but I tend to reach for the orchard as soon as possible; that gives me plenty of time with room to spare to get a more permanent food solution researched.
[Spoiler]
I tend to go for restoration first of all; after that, I set builders on uncovering the leaves from the registry of the dead, for the building skill. Very little walking is involved, so they can gain skill quickly there. After that, there's also a hut to build.

Two starting villagers also already have building skill; it's easy to get three adepts to fix the lift very quickly, if you didn't take too long researching. I tend to cross-train my healer in building; there's not too much for a healer to do until medicine is researched, so without sick people, she will regularly help out with building. That should give you three people who are reasonably skilled builders, if not adept, by the time restoration is researched; only 7,500 tech points spent total, as compared to 65,500.

I also put everybody on research, and cross-train several researchers as farmers; they'll go and help farm when food gets low, and back to research otherwise.
[/Spoiler]

No, I've generally got by with just the one fruit tree - plus of course, a lot of mushrooms! Once, with a lot of luck in getting duplicate rare collectibles, I got fishing before the (first) tree had even matured! It is important not to expand the tribe beyoyond the original eight villagers, although I did manage with "newcomers" from events a couple of times.