For tips making food points:
The "Memory" game is your best friend! I like to use my own memory until about lvl 8 or so; then I write down where everything is, and turn over all the pairs at once at the end because multiple matches in a row doubles your reward for each successive match. You want to get at least 10k score because that means you get 1k food points from it! That's the most you can get, it maxes out at that, and you can only turn in your score for food once a day, but...
that's still 1k a day.
Your two tricks to get that high are, 1) point rewards double for every match in a row, so save up your knowledge of where things are and do them all at once, as much as you can
and, 2) if you're really stuck -use a cheat and take notes.
Digging really does help, too. You can also sometimes get some food points by offering to feed and play with other peoples' knuffels, and they pay you by how many points you fed/played with them (they can see the point totals; it resets each month but until then...)
Of course, if you can donate, your very quickest way of getting

is by selling

They're worth a lot on the Market!
Good luck!