So you're a minor house on Bear Island five years before book one. Fair enough.
Deliver a message to the Mormont's keep (can't find the name of it). Slaveship spotted near the shore. Hand it to Lord Jorah, he has no coin to spare at the moment but instead offers you a bow he recently finished carving. He calls for Longclaw and runs out to deal with the slavers. You overhear servants discussing how Lady Lynesse has not gotten out of bed except to use the privy in four days. On the way home you encounter a bear. This is a Westerosi bear so it's like thirteen feet tall. You can sneak, climb a tree, you have a dagger, and the bow (strung and with arrows). Make it home alive to finish the mission.
Sail north across the Bay of Ice to the Frozen Shore to hunt seal and walrus. You're on a boat and you have spears, nets, and arrows to hunt with. Watch out for whales and kraken. If you land on the Frozen Shore you'll be attacked by followers of the Great Walrus. You can kill and loot a few of them, but there's always too many to survive a fight with. Collect ten seal skins and twenty walrus tusks to finish the mission.
The wind blows you off course on the way home and you approach Bear Island from the west. There you see the slaveship you warned Lord Jorah of earlier. It's anchored near shore and there are people talking on the beach so you land quietly around a bend and sneak over for a better look. There you see Lord Jorah selling the poachers to the slavers. A slaver's dog smells you and starts going nuts so everyone starts investigating. Sneak away successfully to complete the mission. Optional to untie the poachers to create a diversion.
When you arrive home you tell your father what you have seen. He decides to think on his decision and asks you to fetch his maester. Go through the keep, find the maester, then the three of you discuss it. Your father decides to send a raven to Winterfell as well as to send you personally to seek an audience with Lord Eddard and tell what you've seen.
And then it can go on from there. Now you're on the mainland and you've Forrest Gumped your way into what was going on there around that time. I've never actually played a D&D style RPG like that but if I were writing a videogame or something based on the idea it could go like that.