What alternative stuff is there for hamsters in Baja?

I live in Baja and plan to get a hamster in the next day or two. I’ve had hamsters, but that was before when I lived in WA. Basically I want to know what tropical fruits are ok, like papaya and guava, and also if plain straw is good for bedding. Any information in general is appreciated.

What do parakeets eat? Can they eat lettuce and grapes and stuff that people eat?

I am researching parakeets because i might get one, so any other advice would also help!