Dolly, Richard320 has been at this a lot longer than I have ... I've only had my own pool for a little over two weeks. So if we give conflicting advice, favor his over mine.
I also have a new Intex metal frame pool, just with more volume. Before I found this forum and learned about Trouble Free Pool care, I had thrown three pucks (generic name for the puck chemical: tri-chlor) into it my pool straight away, as well as
another sanitizer called di-chlor. Only afterwards did I find this forum.
Long story short -- the chlorinators I had added raised the cyanuric acid level of my pool water from 0 to 60. Not a terrible outcome, BUT -- I was wisely advised by Richard and some others here to stop using pucks and di-chlor and start using unscented plain ol' bleach. You know what plain bleach is.
This is also bleach, just more concentrated and with a different name. Walmart sells that stronger bleach, which saves a little money because you're using less every application. But your pool is small enough that you'll not see gigantic savings ... just as soon use regular ol' bleach. Just remember -- no "fresh scent" bleach or anything like that. No "splashproof" bleach, either -- plain Jane bleach.
As for dosing the bleach, the Pool Calculator link I gave above will help. On this forum, you will be advised to perform a water test to determine levels of chlorine, cyanuric acid, pH, etc. in your pool water right now -- that will help dose your pool more accurately. Take a breath, though -- while water testing at home can seem daunting, it can readily be done at a basic level to get a fundamental understanding of what's happening with your water. The learning curve is not steep.
Now, on this next point, I will totally defer to more experienced forum members: the size of your pool will be forgiving of maintenance mistakes because it's easier to drain some or all of the water out and make adjustments if needed. You could even drain in full and start over whenever the water gets to far gone. For me, with a pool much like yours, I really want to avoid draining/refilling with any frequency. That calculus might be totally different for you.
I hope this helps, and I hope I am not stepping on the more experienced folks' toes here. I will take my lumps if so.