If you've been playing the world-building home game this week, you should have a good idea of your world and your character's place in it. What you want to do next is tailor your world to better suit your story. If you're an outliner, this will be a little easier, as you'll have something to reference. If you're a pantser, then just think about the possibilities and make notes or whatever works for your process. This is a great time to brainstorm and see what you can come up with.
Start by looking at your core conflict. Are there any world building factors that could affect this? Would things be more compelling if you shifted your protag from one social class to another? Or gave them a relationship with someone in a different social class? What you want to look for are ways the world itself can cause hardships for your protag. You should have figured out what their normal day was like, so now think about ways to cause problems in that day, compounded with the story problem you've thrown in their lap.
One of the ways I did this with The Shifter, was to put Nya outside the accepted social class, but gave her a sister inside the social class. Someone close to her who had advantages she didn't have, which caused not only external issues, but internal conflicts as well. I compounded this with the story problem of Nya having to keep her shifting ability a secret or end up being used as a weapon against her own people. Nya is the kind of person who helps when she sees someone in trouble, but when she does, she risks exposing her secret and drags her sister into it as well.
Next, look for ways everyday life might cause problems. If they link into the core conflict that's great, but they don't have to. What are the challenges specific to your protag in this world? How might you use those challenges to create obstacles or conflicts in your protag's goals? They might be people, or situations, climate, responsibilities, habits, whatever. Look for things that would make anything your protag did a little harder because they'd have to overcome this issue before they could even take on the bigger problem. It can be minor annoyances or major obstacles.
Nya's constant "one the verge of starvation" was something I used. Finding work and food was hard for her, so when she was given an opportunity to make a lot of easy money, it was terribly hard for her to say no, even if she knew it was wrong to say yes. It also put her in a vulnerable position and made her make decisions she wouldn't have made had she had a steady job, room and board, and regular meals.
Now flip it around and look at your plot points and character goals. What problems or scenes do you have that could be deepened or made more exciting if you connected it to something in your world building files? A chase scene that would be more tense if the weather wasn't cooperating, or a relationship problem that would also cause troubles if it was at work. Are there any scenes that might influence some aspect of your world and make it better? For example, a situation that could be made worse if you tweaked a particular detail.
This is how my pain merchants were born. I knew I wanted people to buy and sell pain, but I didn't think about the darker black market aspect of it until I saw opportunities for Nya to interact with them. Her always scrambling for money naturally made me think about the shady side of the pain business, and how they might take advantage of someone in Nya's position. And if they'd take advantage of her, who else might they do it to? This led directly to one of the more heart-breaking scenes in the novel, because not only the poor are taken advantage of by these guys, and the problem became so much more widespread once I started looking at the bigger ramifications.
Don't be afraid to tweak and change things as both plot and world develop. Just like plotting, world building is an evolutionary process and ideas can feed off each other and help you develop a rich world that has depth. If something strikes you, run with it and see what else it might affect. You never know where one "wouldn't it be cool if...?" might lead.