well i am a rookie here, but i have had my tank up and running for years, maybe i am lucky but i have the setup you are wanting. I bought a 10 gal setup from walmart. think i did get the small heater extra. Did everything you said, didn't get fish that day. Took it home, set it up, gravel fake plants, heater and filter. Added some chemicals and let it run a few days.
Them i went and got 10 neons and a pleco. been going strong every since.
Everyone says dont get a pleco for a 10 gallon. I have always had 1 in my 10. IDK Ive had probly a dozen over the years. Get em small, once they get big, 3" i catch em, and take em to pet store and trade for a small one again. I had one get 6".
right now i have 1 plec 2 oto cats and 15 neons. Its crowded, but more so from the filter cartiges i have soaking in there preping for the move to a 100gal.
I did upgrade filters a few years ago. I got a 30-60 with 2 filter packs. Every so often I replace one. i dont change the water, I take a pitcher out and water the plants with it, and add it back.
Now, for those that have read this far. I am not saying I am right. Just letting them know what has worked for me. This has worked for me in 4 differant houses, with 4 differant water suppleis. I plan on doing alot better with the 100, of course my plan is for a low maintenance setup with adrip.