You get 28 points to distribute between these stats; each stat must be in the range [1, 6]. Improving a stat gives you a constant improvement in gameplay; no "odd stats are good" as in D&D. Essentially everything you do will be affected by one of your stats; you get to add the stat to any other bonuses you get and roll that many dice. A good distribution could be 6, 5, 5, 4, 3, 2, 2, 1. Note that ability scores are very difficult to increase, especially in one-shot campaigns.
Next, skills. You get one main skill and five minor skills. Skills represent things you are good at doing. Every time you do something, you get to apply at most one of your skills to the number of dice you get to roll. Your primary ability should be very general; our party has abilities like "Smashy Smashy" (for the troll) and "Find/Exploit? weaknesses" (for the rogue). Primary abilities should be central to your character concept. Secondary skills are more specific; examples include "run quickly", "steal", "make magic food", "resist fire", "bash down walls", and so on. Secondary skills are what you spend most of your experience points on, and they can also be improved by items.
Magic falls under this area as well. Any one of your skills (primary or secondary) may be a magical realm (e.g. fire magic, illusion magic, chaos magic, knowledge magic, et cetera). A primary skill gives you four magic words (nouns, verbs, adjectives, etc.); a secondary skill gives you two. You will use these words to determine what kinds of effects you get when you cast spells. Examples from our campaign include "shininess", "delicious", "madness", "leaf", and "grow". Again, these should be versatile, but if you go overboard ("modify", "kill", and the like), you probably won't get past the GMs. Remember, spellcasting depends on your Intelligence. I won't go into the actual mechanics of casting spells right now.
You get 18 points to distribute between your skills and your hitpoints. You must have between 1 and 4 points in each of those six values. It is recommended that you maximize your primary ability, since if you choose it correctly, you'll be using it a lot (and if you aren't using it a lot, then why is it your primary ability?). Putting points into spellcasting abilities improves your ability to cast them, thereby making it more likely that you can get the spell off, as well as increasing the effects of the spell.
You get two items to start with. Items have durability and bonuses; for starting items, the sum of these two values must be four or less. Bonuses increase your skills or give you new ones (so a +2 belt of dodging gives you two extra dice when you try to dodge something). Alternatively, you can improve ability scores for four times the cost of improving skill scores (so you can just afford to make a +1 amulet of Intelligence with no durability). Durability acts as a buffer between the world and the item's bonuses. When something tries to damage your item, the durability attempts to absorb the damage; any damage that makes it through is subtracted from the item's bonuses.
You get eight points to distribute between Wealth and Provisions. The former can be used to buy things, the latter to find things in your pack. When you want to find/buy an item, you expend wealth or provisions while making an Intelligence (for finding) or Presence/Charisma? (for buying) check to see if the item exists. If so, you lose the provisions or wealth and gain the item. If not, you keep your supplies but the item does not exist here. Note that characters do not carry important items in their provisions; provisions are for generic adventuring supplies (lanterns, blankets, rope, healing potions, herbs, but no Overcompensatingly Big Sword of Breaking Skulls +6). Wealth, in contrast, can be used to obtain just about anything; you just need to find a vendor first. You start with zero experience.
Here's a sample starting character sheet:
STR: 6 Primary skill: Smashy Smashy +4 CON: 5 Secondary skills: DEX: 5 Thick-Skinned +2 AGI: 3 Wall-Bashing +1 INT: 1 Packrat +3 WIS: 3 Iron Digestive System +2 PRE: 4 Really Loud Voice +2 CHA: 1 HP: 4 Items: Vorpal Sledgehammer (+2 damage dice, 2 durability) Spiky Plate Armor (+2 damage reduction dice, 2 durability) Wealth: 2 Provisions: 6