If the clothes are loose, casual clothes and pants will be OK with simple straight pants, so that the top and bottom are more coordinated.
If the color is dark, it is best to wear dark pants to avoid top-heaviness. If you especially like light pants, shoes should be dark. The dark color mentioned here is not necessarily black, but also dark blue and dark gray. The most important thing is to see if you like yourself. Others can only give you advice, and ultimately it depends on yourself.