|The Squire from The Canterbury Tales|
Characters like this often get framed as fighters, as if fighters were just the default human adventurer. This dilutes the concept of the fighter as a trained specialist in arms and armament.
You could also play the character as level 0. This works if everyone else is also staring at level 0 and your walking into a funnel. But the level 0 characters are supposed to be what B/X calls Normal Humans. Normal Humans are explicitly not adventuring types. And the assistant pig-keepers of the world may be naive and unskilled, but they are still definitely adventurers.
Let's take a look at the Normal Human.
Normal HumanHit Points: 1-4Save: Death Ray 14; Wands 15; Paralysis 16; Breath 17; Spells 17 (that is, worse by a lot than any classed character)To Hit/AC: 11/9; 12/8; 13/7; 14/6; 15/5; 16/4; 17/3; 18/2; 19/1; 20/0 (worse than any 1st level classed character)Weapons: 1 weapon, presumably any typeArmor: UnarmoredNormal humans are non-adventurers: Peasants, laborers, artisans, scholars, nobles, whatever.Hit points represent how hardy a normal human is. The very young, sickly, or elderly has 1, a blacksmith has 4.Normal humans have skills, and these skills increase with life experience, but there is no need for this to have a game effect. There is no mechanical difference between an apprentice baker and a master baker.If a normal human finds themselves in adventurous circumstances, they might accrue adventuring experience, represented by Experience Points. Once a normal human has Experience Points, they should be assigned a class.
So, let's look at an adventurer class without any specific class benefits.
Innocent AbroadRequirements: NonePrime Requisite: NoneHit Points: 1d4Save as ThiefWeapons: AnyArmor: Shields; Any armor except Plate Mail1 Naif 1d4 02 Tourist 2d4 8003 Traveler 3d4 1600At level 3, an Innocent Abroad is no longer so innocent, and must select a class, proceeding as either a Level One Fighter, Level One Magic User, Level Two Thief, or Level Two Cleric. All of their XP transfer over to their new class. They keep the hit points generated from 3d4, but roll their new classes hit die next time they advance a level.
The mechanical advantage of playing an Innocent Abroad and surviving is slight increase in hit points over a classed character with 1600 XP.