The Lost Realm and Angmar Cycle have locations with travel effects that tell you to do things like "take the top undead from the discard pile" or "engage a warg from the staging area" etc

Are these things you do if you can or are they like travel costs where you cant travel if you can't meet the requirement.

I've been playing since core, so I'm going to praise the game designers for still making my brain think too hard about this stuff in a noob sounding way. This is what happens when you play 12 hours over the weekend. Brain = mush + defeat

4.6. Travel Effects

Some location cards have travel effects, which are denoted by a bold " Travel :" trigger on a card. Travel effects are costs or restrictions that some or all players must pay or meet in order to travel to that location. If the players cannot fulfill the requirement of a location's travel effect, the players cannot travel to that location.