So I'm having a bit of trouble getting the ball rolling. I know what I want to happen - I want my main character to travel across the continent and overcome six challenges. But I don't know how to go about starting that journey or introducing my main character.
Hmm, that's a bit tricky! I find openings pretty difficult, too. It's hard to figure out where to start. That said, here are some ideas -
Maybe throw your character head-on into one of the challenges? The character might not even know why they have to do that challenge, but they're stuck in it anyway, and they have to adapt. Jumping right into the action (as long as you explain enough for the reader to know what's going on) is a perfectly fine way to start a novel.
Your character could also be chosen for these challenges, whether by some supernatural force (if it's fantasy), or some governing entity (I don't know the context of your story, but maybe your character's government or another organization can choose them to tackle these challenges).
If you're going to introduce your character, I'd try to avoid an infodump at first. Say as much as you need to, to make the reader understand, but don't tell their entire back story in one go. Maybe have them interact with another character, or describe how they interact with their world. As it stands right now, I think introducing them directly into the conflict is the best idea, but I'm also someone who writes pretty plot-heavy stuff, and not slower-paced character-driven stuff.
Also, definitely include a reason for the journey. Someone going on a journey with challenges for no reason isn't a very engaging story, so the character should definitely have reasons for doing what they do. If those reasons are the main part of the conflict, all the better.
Anyway, this is just a start, but I hope it helps! Remember - conflict is key (whether it's internal or external). Good luck!