You earn XP for the cyphers that you spend on improve yourself or the world. This doesn't mean your normal everyday needs like rations, living expenses, or things of the like. You do get XP for spending cyphers to improve Sorren's Landing by investing in businesses, buying custom gear, carousing when you get to town, or bringing back trophies from large monsters.
Next level x 300 cyphers.
Example: Level 2 = 600 cyphers
When you donate your cyphers to a business, they can grow the business to offer you more
There's plenty of reasons to buy custom gear. Could be something as simple as customizing some armor, or something like a potion that would purify any food and provide me with sustenance, or a cream you put on your hands that allows you to walls, or special deployable barricade, etc.
These things require experts and cost money. If you find the expert and spend the money you get XP equal to the amount of cyphers it costs.
Note: if you have a hero that can craft, their final product in most cases will be better quality than what you can hire someone to produce, but you do not earn XP for it.
This is the easiest way to earn XP. Spending cyphers for carousing in when you are in town. This can entail a few different types of carousing. Base cost for carousing of any kinds is 10 x d6 cyphers. Whatever the cost, roll a d10 and the GM will let you know the results of the carousing
You spend all of your time living and surviving on travel rations. Dried meats, dried produce, hard tack, cheese that may as well be hard tack. Spending your money on good quality food is a splurge.
Carousing with the other vagabonds and the locals is the best way to gather up some rumors. You never know where the party my lead you, but no risk no reward.
Donating things to the city means you are not getting paid for it. You don't earn as much XP from this, but you improve the town. The improvement is based on what is donated
Helps you to learn the purpose and effects of one of the many strange objects pulled from the wastes. This represents you buying information, renting valuable books, and otherwise scouring Sorren's landing for hints about the objects.
This requires the least amount of cyphers and earns you the least # of cyphers, but is also by far the safest option. This represents you putting your character out there in the social circles to make yourself known to the locals. Spend 25 cyphers and answer a question asked by the GM. After you've answered the question you earn 25 XP.