Saltwater to freshwater? You've got it backwards.
For a freshwater tank, take the maintenance you were doing with the salwater, cut it in a third, and do half that.
Easy fresh water fish for a tank that size? Mollies/platies, sword tails, Guppies (especially if you want to try breeding them get one male and two females, but beware, you'll then be looking for people to give them to or ways to get rid of them - Like feeding them to fish in a different tank), Goldfish, zebra danios, Tetras - though they can get sick.
10 gallon tank = 10 inches of fish (full grown).
Change 20% of the water once every two weeks ish.
Hang on back filter will be sufficient. Change filter when dirty. Could also do undergravel, but it's a small tank, so probably not needed, especially if you dolive plants.
Plants-
Get good lights, with the right bulbs, probably need mutlitple bulb, wouldn't use halide on that samll of a tank, it would heat it up too much. Leave them on long enough. If it's daytime outside, light is on, night time, light is off.
Use good substrate- if you can also get a small amount from a tank that's already going. This makes the initial cycling of the tank better. Use medium size. Too small crushes the roots, too big and the roots cant spread out.
Gravel deeper in back, shallow at front.
Rinse new gravel first before putting it in, until the water runs clear through it. Use colander. Don't do when women are home.
Small plants up front.
Sword plants are easy, as are Lillies.
Fill tank up with water, turn on filter. Set temperature on heater. (unless goldfish who like cooler tanks) Wait a week.
Plant your plants.
Wait a week.
Buy your fish.
Put bag in fish tank, acclimate, etc.
Tadah!
Use siphon to clean tank for partial water changes.