First time owner

Never kept fish before but I have read a lot about keeping fish before I begin mine. So basically I want to recreate the Amazon river basin in a 10 gallon that I found in my house and have a few questions:

1. Other than the amazon swords and cabombas what other plants can I plant that are from that region (are there any which look like grass?) and what kind of light should I get (would it be better to get fluorescent or incandescent?).

2. I would like to 4 corydoras, maybe 6-8 cardinal tetras, and a betta (not a necessity) but this is probably way too much for the bioload. Would the cory and tetras be fine or would there be too much stress? It would just mean I have to change the water more often right (no harm done to the fish)?

3. The 10 gallon is pretty old (I made sure to clean it thoroughly with tap water) and the equipment with it (hood, filters, etc.) are very old and haven't been used in a long time (+2 years), is it still safe to use them or should I go and get new ones? I'm asking this since all the expenses would be paid out of my own (teenage) wallet, and would like to try and keep expenses down.

Yeah I've been reading about the cycling process from numerous sources and was thinking about the fishless cycle (easiest way would be to buy the ammonia kits right?) unless another method is quicker.
And I was became interested in the hobby again after quite a while and remembered a fish tank I saw somewhere around the house, I think i'm going to be addicted already
Oh and I know the bettas are from Southeast Asia I just wanted a single "showy" species, would a gourami be better? The single species is negligible if the tank is already considered too overly stocked (can someone help me on whether it is already?)