Welcome to the forums and thus the community, growing is much more complex than most give it credit. It will take time and effort as well as money but the learning process and the reward is something that you will never regret or forget.
There as so many different methods you can go with and so many different products.
Did you buy the spider farmer kit or just a different tent? Heads up your going to want an AC infinity duct fan due to its controller, this will make many processes much easier so I highly recommend ensuring you get one of those.
Also an aphera PH meter kit, one with calibrating fluid. PH meters are a little pricey but a good one is worth its weight in gold when it comes to growing.
Since your doing hydro the learning curb will be steeper but you’ll learn faster by failing more and ultimately the growth will be unmatched if you can prefect it. Sometimes building your own system is better due to function and cost @Myfriendis410 and @peachfuzz will be more help with that.
For now I would say get a PH meter, a TDS meter (doesn’t matter to much which one), figure out what nutrient you want to use (Jack’s is recommended due to cost savings and performance, ask more about this if your interested we can tell you what to buy)
And ensure your setup is what you want before you open boxes and can’t return things.
The little seedlings you have growing are growing so far so keep it up.
Early on its important to keep humidity high and the air warm, print off a cannabis VPD chart to understand where you want your humidity and temperature to be ideally for each phase.
Also download photone on your phone (use sunlight setting in the app) and measure your DLI (daily light intrical) to choose your lights height and power as the DLI is the real measurement you’ll want to focus on.
Learn more here
Ask questions but do alot of reading, it will be your best use of time.