For the Journal you have to check all of the entries. Anything without a Mickey head next to it means you have to complete that task. I don't think you can find out your percentage until you beat the game. You just have keep checking through your journal to see what things you have left to accomplish.
As for the Gummi missions you can see your rankings at each gate. I don't think they keep detailed stats on that either, but then I really don't mess with the Gummi missions too much so I'm not entirely sure.