I've gotten some medals that have skills on them but I'm not so sure how to level them up, does anyone know how?

Thanks!

You can level up skills by using the medals in combat. I think it has to do with the amount of lux you gain while that medal is equipped, cause I gained some level ups after fighting a raid boss. Hope that helps

Using them in combat, can I just farm quest stages then?

Yep, as long as that medal is equipped.

I've gotten some medals that have skills on them but I'm not so sure how to level them up, does anyone know how?Thanks!

You also can put skills to other medals by putting the medal with the skill in the level up slot of the medal that doesn't have one. It resets the lv. but you keep the percent and I think You can level it of more.