Try for a goal that's reasonable, then gradually raise it.
I knew a kid in high school who was very smart. His family was poor but he was a good student with a particular interest in science. He was a shy kid, had no girl friend and most people thought he was, what would be called today, a nerd.
He was also no good at sports. But we all had to play sports because it was "good for us." He played basketball poorly and hated it. He was a bit better at baseball because he could hit the ball when no one else could. When we asked him about it he said it was a matter of mathematics, which we didn't understand.
But one year the school decided to include track and field events as part of it's athletic curriculum. So he ran, slowly. He jumped, clumsily. The shot was too heavy for him and he threw his arm out trying to fling the javelin. But one day, out of curiosity, he picked up the discus and tossed it. He decided he liked it and started practicing. The coach encouraged him.
The following year the school joined a league and we competed. He watched carefully at how the other boys threw it. Soon he kept winning because he continually threw it further than anyone else. When we asked him what the secret was he said it was a matter of physics, which we also didn't understand.
He explain it to me once. He said that when you throw the discus you pivot, as you do with the shot or the hammer. But he said he held his discus arm back behind him for as long as he could while he was pivoting, until the very last moment, so that when he threw it he had the force of the pivot, plus a whipping action with his arm.
I started using his system and did very well myself.
Well, he got a full scholarship to a Midwestern college as a discus thrower and graduated with a Bachelor of Science degree, naturally.
I've lost touch with him but I'll bet he's discovering new things, inventing better systems and, who knows, breaking records someplace.