Hi welcome to Fish Lore
Please consider cycling your tank with out fish. It's less work and stress for you an healthier for your fish.
Most bettas don't make good community fish. You could try 1 betta and a few cories or otos. Although sometimes that won't work so you'd need another tank in case you had to seperate them.
Here's our care guide on bettas:
Welcome and Betta Care Guide - Please Read First!!!
I don't know much about Dwarf Gourami's, but I think 1 and a few cories or otos should work (with out the betta)
Or a few guppies.....3 or 4 (of 1 sex) and a few otos.
Although a nice tank, that price is pretty steep. Walmart has a rectangle 10g kit for a lot less.
Good luck
