you need hosting, domain to start a blog
and after building is done, you have to seo on top google
last, money comes your pocket when your site is on top google
Use own WordPress or Google free Blogger plateform for hosting your blog but always use with your Own Domain.
Checklist for Starting a Blog
1. Idea
2. Memorable Domain Name
3. Fast Hosting
4. Eyecatching and Lightweight Theme
5. Unique and Great Content(700+ Words)
6. Promotion
7. Email Collecting
8. Make money through Ads or Affliate Marketing.
Buy a hosting and domain for your blog. Develop your website and then add content (blog posts). Then wait few days and then start SEO of your website. You can do its Social Media Marketing too.
If you wanna earn money from your personal blog, than remember the most important thing is CONTENT. No matter what you try to do, in a long run, CONTENT will define your blog.
Search and buy niche related domain name and hosting service. Start blog with free but responsive theme of WordPress. I recommend WordPress because this platform is easy to manage various types of content like text, images, video and audio files(may be you require plugin)