For this guide, keep in mind that it'll only consider the feats and story of the first season of Goblin Slayer. This also means that there may be some spoilers for the character, so be warned. Lastly, this guide is only going to look at officially published content for Dungeons & Dragons 5th Edition, so this means no homebrew or unofficial content.
At this point, the character is set for use in any 5e adventure or one-shot. Depending on the rules of the game, there may be extra equipment that's able to be purchased. If this is the case, look at grabbing things like mirrors, throwing knives, a grappling hook or other adventuring supplies. Part of Goblin Slayer's combat strategy is using everything and anything to his advantage, and using the more mundane items of 5e could lead to some exciting and fun moments.
The Dungeons and Dragons 5e character built by this guide should be a strong, versatile combat character with emphasis on using anything to his advantage. Much like in the Goblin Slayer anime, as long as this character has a party at his back to help cover his weaknesses, there shouldn't be a goblin in the Monster Manual that can stop him.