how do I configure a new Oracle 11g instance to match the configuration of the old Oracle 10g server
You don't want them to be running with the same parameters in the first place. Very likely that you want to enable the 11g features. Things that you might want to make sure to be at least equal size are the memory footprint, temp tablespaces and undo tablespaces.

In Oracle 11g you might be tempted to use Autmatic Memory Management. There are some issues with it so it might be smarter to configure your shared pool and database buffer according to the 10g database. In the run check if you are not over or undersized.

Best is to hire a dba to help you with the setup, next best is to dive into Oracle® Database 2 Day DBA 11g Release 2 (11.2) There is a lot to learn from.