Newbie - Query from table

Hello,

I am new to access so please bare with me I have been working with excel and now seen the light

I have a table with about 30 fields and I need to run a query on a single field and return all the records with a value (Variable). Some of the records have no vakue in this record and these are the ones i dont want to see.

Forms: is there a way yo default a field in a form based on the previous record? i.e. location: if you add a further record the new record populates the last entered location? Is there also a way to copy a previous record and duplicate it and populate some of the fields that are defined?

Lastly, how do you set up a table field to see who entered the data and at what time

Any help would be greatly appreciated

Thanks in advance.

GC