Most blogs will take a few years before they start becoming profitable as in covering the hosting and domain fees.
Then maybe 5 years in if you work hard on your blog adding content and promoting it then you could make a living from the blog.
But sometimes it can take longer than 5 years to make what you might consider a full time income from your blog.
There's no guarantee of making a living from your blog either. If you don't continue to publish great content and target the right keywords then you won't get the required website traffic to earn a living.