How to Level Up
This guide contains information on how to increase the power of your character by finding the right place to level up in Demon's Souls.
As you travel and explore the lands of Demon's Souls, you'll obtain Souls as a form of currency, which can be used to buy items from merchants - but more importantly, this currency can also be used to level up, increasing what is known as your character's "Soul Level".
In order to level up, you'll have to stop your current adventure and return to the area known as The Nexus - the hub area you find after the Tutorial. You'll meet the Maiden in Black here, and she is the only character you can interact with to exchange your Souls currency to level up and increase in your choice of attributes.
You'll usually find the Maiden Black at the other end of the large pool of water in the middle of The Nexus, though she can appear in other spots - but always around the main area around the Archstones. When you speak to her, you can simply ask to "Seek Soul Power", which will take you to a level up screen.
In this menu, you'll see your character's current stats, their current level, and how many Souls are required to reach the next level. If you have met with requirement, you can choose one of the attributes in the bottom left corner to increase, and you'll see the benefits of increasing that attributes as your stats turn blue on the right section.
You can see what increasing each stat does before committing to an option, and once you have chosen the attribute you wish to increase as you level up, hit the confirm button, and your Souls will be spent.