I am a complete newb. I have a partially finished lawnmower blade I started hammering.. and it is still sitting in the shed waiting, two months later, for me to pick it up again.
Why? Because, in spite of how easy this is made to look on TV and Youtube, once you pick up that hammer and start swinging... you realize that all those hours and years spent by the blacksmiths and bladesmiths honing their skills, the hammer is literally an extension of their arm, and they can make those minor adjustments in swing, that correct the previous strike's slight miscalculation.
You will learn very quickly how difficult it can be to planish, as well as how to hold the heat on the metal when you are hammering it.
Every blow of the hammer causes not just the reaction you wanted, but others as well. You will be constantly compensating and correcting.
And... it is a very addictive thing. A few on here have seen my bottle openers. And the difference between my first and my fifth was huge. You can progress and get much better.
Your hammer control will get to a better level with every swing....
And you better pack a lunch, because this is NOT a sprint. It is most certainly a marathon. My admiration and awe of the bladesmiths just grew once I got to swinging my own hammer, to the point where I plan on taking several more months of just learning the blacksmith basics before I again try a blade.