First of all, I'm really sorry if it seems like we're picking on you. We're honestly not. It's just so frustrating sometimes, hearing about pet shop employees who steer people SO wrong. Anyway, moving on...
I think the best thing you can do is a fishless cycle. I know it's hard to be patient when you're excited to have fish in your tank, but a fishless cycle really is the best thing for the health of your fish. While there are many fish hardy enough to survive a cycle, the process is still incredibly stressful, and ammonia and nitrites at any level cause permanent internal damage and decrease gill function.
However, that said, if you are set on cycling with fish, I would not recommend doing it with neon tetras. Tetras in general are not really hardy enough for a fishy cycle, and neons especially can often come from weak stock. Also, be sure to keep in mind that you'll have to stock the rest of your tank around the compatibility of the fish you use to cycle it.
Do you have any idea what you're interested in keeping in the tank? I know the options are kind of overwhelming at first, but do you know what kind of look you're going for? For example, do you want just 2 or 3 medium sized fish, or would you prefer a couple groups of small community fish? Or maybe a combination of the two, with a small school of little fish and one "centrepiece" fish? If any of these seem more appealing than the other, that would be a great starting point, and then everyone here can start giving you appropriate stocking suggestions.
