Hey there, welcome to AQ.
1) I personally pluck out as many snails as I can during water changes. Puffers are a good remedy, they won't eat up your tetras (unless they're like the size of your computer mouse) but once your snails are all gone you have to keep it for the rest of its life or pass it on to someone else.
2) Look into getting a fan set, either commercial or DIY. There's a good article on petfrd.com, look here. I used that to build my own fans, quiet and cheap. Beats those commercial ones that are occasionally noisy and bulky hands-down.
3) I personally find the Ferka range of fertilisers attractive, or the Seachem range is good. Read up more on what plants need in addition to CO2 and light here. You can go into PMDD (Poor man's daily drops/dosage) if you want to, but it's a rather technical course that you might want to leave for later when you get more interested in planted tanks.
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