new to reef keeping

I'm thinking of starting a 55-gallon reef with maybe 4 fish but mainly critters and soft coral. Can someone help with the best filtration for a beginner ? I dont want a sump seems to difficult and time consuming. I have always had freshwater and have 2 20 gallon cichild tanks. I have found a 55-gallon tank and stand for 50 bucks can't really pass it up. My kids want a reef and want to help so i am looking into this any help or advice would be gladly appreciated. Thank you