Build a blog on about healthy lifestyle and wellness tips. These are timeless topics with a broad audience and you will find many similar blog ideas around.
This will interest someone in health and wellness field, of course. Articles could encompass fitness routines, healthy recipes, or articles/advice on mental health. You can also cover various health conditions and preventives.
Once gained popularity and traffic, you can do tie ups with wellness product/service brands, and sponsored content from health-related businesses. Your target audience will be everyone interested in a general good health – which includes almost everyone.
As mentioned earlier, this is popular and evergreen niche. Only sky is the limit!
Blog Name Idea: HealthUrge.com