The information below is to help assess what your expectations are and what resources are necessary to meet them. If you don't know answers to the questions it's perfectly fine to say that.
If so, please indicate whom.
For Tracking Sessions
It's ok to say you don't know.
"Overdubs" means layering on additional tracks of vocals, guitar solos, harmony parts, etc.
24-bit/96kHz will give you higher quality, however if you plan to mix it elsewhere it cannot always be accommodated; Pro Tools LE and many home recording systems for instance.
For Mixing Sessions