when i download someat i put it in documents/rct3/strucure (buildings)wer do i find em i can find rollercoasters but fr some reaseon i cant find any of the 5 buildins i got:huh:

Click on the scenery icon (a tree and a fence), then click on the icon that looks like a frame of a building. After that, I believe there's an "open" button - click on that and select the building you want to place.