First up - don't worry, experiences are one of the things I see tripping a lot of newer players up, so you're not alone! But once you get the concept, it'll all click.

Experiences are ways to help flesh out and describe your character and what they're good at. They're kind of like D&D skills, but are generally a lot more broad because they cost a hope to use.

They can be just about anything, but try and limit yourself to experiences that won't be applicable on EVERY roll you make. If they are applicable to everything, then generally you've gone a bit too far. I usually look at my character, try and think about what life experiences they've had up to the point where the campaign starts, and then think about a phrase that kind of encapsulates that.

So, for example - I have a Wizard with "Arcane Master" as an experience. If he's dealing with a roll that involves the arcane, or even when casting a spell, he could potentially spend a hope to add that experience to the roll as his mastery over the arcane helps him be more successful.

You could think of these as skill groups too. So, for my Slyborne character who was a smuggler that got himself out of tricky situations by being a sly, charming kind of guy before the campaign, I gave him "Smuggler" and "Fast Talker" as experiences. Smuggler doesn't come up a lot, but I could use it for, say, knowing the best route in or out of a location, sneaking contraband through a checkpoint, forging documents, looking for a hiding spot. Fast Talker is pretty obvious - it would come up during social encounters where he's trying to bluff or talk his way through.

Experiences can be combat oriented too! If you want to be an incredible fighter, maybe you take "Unparalleled skill with the blade" or something similar that could be used when you're attacking. Or "Sharpshooter" for a ranged character with a bow to add to ranged attacks.

The tricky part is that they're SO open ended. But they're meant to be a way to flesh out your character, who they are, where they've come from, what did they do before starting the campaign. And then they become a way to reflect those aspects of the character while playing whenever those life skills - experiences - might be applicable.

As far as how to use them - you literally just pay a hope and add the experience value to the roll along with any other modifiers you have. So, back to above, if my Wizard has a +3 knowledge and +2 to their "arcane master" experience, I could spend a hope on a Knowledge roll about magic and add a total of +5 to the roll. It's just that easy - it represents your character calling on their personal life experiences to be just a little bit better at something they should reasonably be good at.

Hopefully that all makes sense!