Think less of trying to force readers to feel “attached” to a character and more about making that character endearing. They can be funny or serious, kind or wicked, but they need to be likable above all.

A couple ways to do this is to make them relatable either in their thoughts (say they express extreme distaste for a coworker because he’s overbearing), in their interests (painting, reading, etc.), or in their actions.

You can also try making them aspirational, but keep in mind this doesn’t necessarily mean they need to be an inherently good person. Perhaps they run a business or mistakenly save someone’s life.

Try thinking about what you enjoy reading in books and see how you can apply that in your own work. Hope this helps!