How do I fix the DPI on my phone?

Excuse me, I'm having some trouble with the DPI on my phone. Could you possibly offer some guidance on how to adjust it? I've noticed that the display seems a bit blurry and I'm wondering if adjusting the DPI settings might help. I'm not particularly tech-savvy, so if you could explain the process in simple terms, that would be greatly appreciated. Also, would adjusting the DPI have any impact on the performance or battery life of my device? Thank you in advance for your assistance.