I use Excel for numerous applications but thought I would give numbers a go. Found that Excel imports okay except for a problem with dates. Easily fixed. Just highlight the date cells and use Inspector to set the date format, even though it may be the same already. Numbers puts a little blue triangle in the top right hand corner of the cell so you know that there is a compatibilty issue. Numbers does not do everything that Excel does. It does do most though.
For help download the PDF manual from Apple support. Heaps of really good instructions and easier to understand than the Help files.
learning something new is fun. Teaching others is more fun