- Go with basic tupperware or rubbermaid containers -- ones that seal to keep food fresh. You could also get a small (or large) cooler. Those also seal well and provide a lot of storage -- which you will eventually need

- No seasoning required -- there is no wood.
- It's all personal preference. Try various levels of RH and find what you like.
BTW, in a sealed container like the above you can get by with less humidification (wood does not seal quite as well as plastic).