If you are wanting to pull a list of contacts that received a particular email campaign but did NOT open it, you can use a contact search with the following structure:
This can be a really valuable list of contacts if you are wanting to re-target to those that have not yet interacted with your campaign.
Similarly, for a specific journey you can run a query like this...
...and for a particular journey stage/email, you can use something like this:
If you are still unsure or are trying to build more complex queries, please feel free to pop up on our live chat and we will be happy to assist further!