Diet concerns

I have a question regarding diet management.
I've recently felt the need to manage my weight, so I've been trying to combine diet and exercise. However, since I'm trying to do this alone, it's not easy to maintain consistency. Rather than trying to lose weight too quickly, I want to reduce body fat without harming my health. I'd like to know which aspect of diet or exercise I should focus on more, and if there are any easy ways to manage it in my daily life. I'm also curious about what I should be careful of when dieting, and if there are any professional methods that can help. I'd appreciate some advice on a diet that fits my lifestyle.