my suggestion...keep it simple!
you'll need nets...scissors pliers and grab a dish sponge (one of those with the handle) and peel out the green pad from it you only want the sponge (this can be used to clean the inside glass)
you mentioned wanting neons so I'm assuming you want nano fish...which tbh are my favorite...
first of all..cycle your tank...grab a few cheap plants like hair grass and put them in there while cycling your tank do 10% water changes every other day (don't over do it and be patient)
and throw some powder fish food after each water change...just a small pinch
the hair grass will literally die while cycling and come back to life again when your tank is cycled...when you can manage to keep those green for about a week your tank should be fine
next...ph pens tds pens etc....forget those....they go for about 20 bucks...you can grab a ph monitor for about 45 which will do the same but in real time
now fish...personally I like endlers some people prefer guppies...(don't mix them as they will interbreed)
then neons..you'll need a patch of white gravel with some decorations on top of it for when the neons breed...don't expect much breeding maybe 1 fish every other month as the rest will get eaten by other fish
guppies or endlers you'll be able to tell when the female is pregnant even being new to the hobby so you should have a small breeding box for them
nothing beats getting a single pair and breeding your own...you'll get that sense of accomplishment that you're doing it right (it'll never go away...just different fish)
next...algae! get a cleaning crew....hillstream loaches look nice I'd grab 2 or 4 of those...you can tell their sex by how they look...female looks round male looks square like he's got bulky "shoulders"
and around 6 oto catfish and 6 habrosus cory
next...shrimp!! they always look cool in any tank...
you got Neocaridina and caridina shrimp...don't mix colors from the same species as they'll interbreed and become brown...
so you could grab let's say yellow neocaridina and white-red caridina...this way you'd have 2 different species of shrimp that can't interbreed
then comes maintenance!
some people like having perfect water conditions....like ro water then chemicals to fix it to keep ph at a certain point...
I honestly like to keep it simple....when my ph reaches a certain value... = gravel vacuum to take out water...and fill it back up
if you're doing straight tap like me..make sure you have carbon active filters in your filtration system and don't EVER do more than 10-15% water changes and wait at least 2 days before another water change
anytime you see people saying 50% water changes or 75% water changes and so on...those are what I call chasers...
they're literally adding RO water and then fixing the water parameters in their tank to match what they want as RO will strip the water of the bad stuff but also the good stuff
eventually your tank will balance itself out to the point water changes will become less frequent always aim for a neutral ph or 7-7.2 and do water changes at 7.6 and you should be fine
always remember...RO water kills fish and chemicals kill fish...be careful when using either and always start slow if you decide to use RO in the future...
if your tap water is on the (harder side/higher ph) you can get a softener go on amazon and search for "shower water filter"
looks like this:
and you can put it under your kitchen sink in your cold water piping that way everytime you take cold water is a bit softer...
it's no RO but will get the job done.
as for heaters...throw them in the garbage...fish will do just fine unless you have crazy hot/cold temps in your house...anything between 60 and 86 fahrenheit is fine
anytime someone tells me a fish has to be at 83.29785 I literally just laugh xD
remember..this is about having fun having fish and enjoy the little buggers, not having work and become a part-time job to have fish which is why most people leave the hobby...
