So, I just tried to do a quest for one of the fighter's guilds and it's one of the hardest things I've ever tried doing. The dungeon is huge and I'm finding impossible to find my objective (to kill an orc) and I'm sure that even if I do I'm gonna get my head bashed in.

So, I ask you, as a Nord Warrior how should I start out in this game? Would you recommend trying a different guild/quest? Should I get some spells? From what I remember, I only have 300 gold coins or so. Any help appreciated.

It's best not to start out with dungeon quests. Hell, even when you're fairly experienced you shouldn't bother, unless you really want to. I'd recommend going around town doing lesser errands for vilalgers at first. Also consider joining a temple or a knightly order - they have some pretty easy quests.

You can decline guild quests without losing reputation. It's best to start off with in-town quest that require you to go to a house and kill an animal or rats first, they're fairly easy and will build up your reputation with the guild.

The huge dungeons are basically a feature of this game. You don't necessarily have to do a lot of them, since for guilds you can sit there declining quests until you find one that doesn't involve a dungeon, but you will have to do a few if you intend to finish the main quest.

My recommendation when exploring dungeons is to do a recursive left wall search. Follow the left wall until you get back to the entrance. Then follow it again until you find a passage you haven't gone down yet, and then follow THAT left wall until you get back to where you started it. Then follow THAT wall again until you find another passage... like that. I actually find it enjoyable.

I've been having trouble starting the main quest. I can't seem to find the Blades agent at the Thirsty Muskrat inn...

There's the name of the town (which will be an inn or lodge community), and then there's the name of the tavern. You'll see an older lady in a brownish orange robe (I think that's the best way to describe her, anyway).

That is the only quest in the game that you should not pass up on, or it makes the game unwinnable.

but I got completely contradictory information: she wrote "the Lynx and Muskrat Inn", at the "Thirsty Muskrat Tavern", in daggerfall. i went to the Lynx and Muskrat Inn, but no one was there.

Sometimes towns are named after taverns. I do not know why, it just is.

My theory is that the community was named after a tavern that used to exist there a long time ago. People moved into the area, competition sprung up, and eventually, the original establishment went out of business... but they still refer to the new town by the old name.