Beginner looking for advice
I am about a month into keeping 2 freshwater tanks. I have a 5 gallon nano cube which I’m currently keeping plants in and a couple shrimp (not shown), and this 20 gallon hexagonal tank with 2 ottos, 3 tetras and 4 ghost shrimp in. I have a heater in both tanks keeping the temperatures at 72 degrees and both have hang on back filters and aerators. My mom had a 90 gallon reef tank that she took amazing care of for 30 years, and a brother who had a 70 gallon reef tank. I have recently gotten into the hobby and want to be the BEST fish keeper I can be. I know that fake plants and decor aren’t great options for keeping fish but my husband really wanted to get the colosseum decor when we were picking up supplies. Eventually I want to replace it with natural hardscape but I don’t have any yet besides what’s shown. I’ve been watching my water levels, and have used r.o. water instead of tap as I have hard water. My goal is a planted community tank and eventually a salt water tank. What are some things I should know and do as a beginner?