Acadia always give newbies a survey consisting of various helpful links.

As far as clothing goes, if it's conforming clothing, you'd highlight the clothing and go to FIGURE====>CONFORM TO=====>FIGURE 1 (or name of the figure you have loaded)

Now when you pose your figure, the clothes will pose with it. MAKE sure when you're applying a pose, you do so to the BODY. I can't tell you how many  times I accidentally applied the pose to the clothing itself and had to press the UNDO button.

Then there is Dynamic Clothing. You  attach dynamic clothing with the FIGURE====>SET FIGURE PARENT. Or OBJECT====>CHANGE PARENT. Find the body part and attach it to that then press okay.