Welcome! Biggest piece of advice is PLEASE take your time, don’t be tempting to fill up the tank and throw in all your pets day 1. Take your time and cycle properly so you can enjoy your fish friends for years to come. I agree with real live rock, also you can save some $ if you find a hobbyist with a mature tank nearby who is willing to part with some rock for less $. I also highly recommend auto top off (ATO) to prevent salinity swings due to evaporation, which is a serious concern for all saltwater tanks but especially smaller ones like your system. Enjoy the process, and don’t be afraid to ask questions!