New to saltwater, switching from fresh water

Hi, I've been freshwater for years, but now that I have a good job, I'm going reef. I've alway wanted a reef tank but couldn't afford it. I am starting 180 g with a 55 g sump/Refugium. I've seen some of the tanks on this forum and am super excited about it!! But I must have patience.. I build the cabinet it rest on. I think it's coming out ok. I'm just about to start the cycling process in the next week or so. So I'm at the very start