When you have your protagonist find a sword on the side of the road, he’s going to have to fight with that thing at some point. If you want to write his fight scenes in a way that does not suck, you have to make some decisions about how you want to present combat in your storytelling.
You can go heavy on blow-by-blow choreography, or light. You can decide how to handle the interplay of emotional stakes and practical stakes. You can focus more on the interiority of how it feels to be in that fight than on what the character’s body is doing and experiencing. Any approach you might take works better if you know something about the fighting style you’re writing about.
I should note that I was, very briefly, the worst varsity fencer at Vassar.