Hi there, I imagine that you are getting through the suggested reading guides. I imagine that you will find a lot of comments that 10 gallon is going to be very small and difficult, especially for a newcomer.
I suggest you read up on nano tanks in particular. Alternatively, if you were to choose to go bigger, the 10 gallon may be useful for quarantine, or as a sump/refugium.
Alternatively, if you are new to fishkeeping in general, a 10gallon freshwater tank may be a good first step, and you can get the nitrogen cycle and pH under control, rather than going straight to Ca, K Mg issues.