Welcome to the world of fishies!
I see various Molly, Platy, and Black Widow Tetra. You can click on the shaded names to view the species profile and learn more about their requirements.
When you get through the cycle and have stabilized your water parameters, you'll want to have at least 6 Black Widow Tetra. Do NOT add any more fish until you're cycled, and then only slowly! Always thoroughly research your aquarium decisions, and never be afraid to ask us for help. We're here for you!
You'll want to do a 50% water change whenever you have readings of Ammonia or Nitrite that is greater than 0ppm, or Nitrate greater than 20ppm, or weekly (whichever comes first). Since you have chosen to cycle your tank with fish in it, you're responsible for helping them survive this toxic process with minimal damage to their systems.
To hurry your cycle along, and to further help protect your fish, there are two very helpful things you can do (besides large water changes). You can add a whole bunch of fast-growing floating plants to help suck up the toxic ammonia, etc. (If you post the details of your lighting, we can help you pick out appropriate plants. Water Sprite is generally a good floating plant for just about anybody.)
You can also "seed" your tank with biomedia from an established, HEALTHY tank. Filter material, substrate, decor, and plants can be used. These are surfaces that will contain beneficial bacteria that will help quicken your cycle.
So keep up on those water changes, and keep us posted! Good luck!