Its ok to ask things like these, not a stupid question at all dear!
As I understand Woodland Realm is the kingdom of silvan elves (woodland elves) in northern Mirkwood. And In the movies they visited Evenking’s Halls. Which is located northeast in Mirkwood.
Also Legolas’ title is Prince of the Woodland Realm and Thranduil’s King of the Woodland realm. So thranduil ruled woodland realm.
(I’m always afraid of answering middle-earth questions bc I am afraid I get the facts wrong because I do not know 100% how things are. Even though I know a lot. I hate to be wrong).