It is entirely up to you which route you wish to take.
If it was me I will register a domain and install Wordpress via (cPanel) or FTP on a website hosting server.
Most of the top bloggers eg. John Chow, Shoemoney etc. recommend to have a wordpress blog standalone on own server or hosting comapny server with own domain name.
From there you can work on getting traffic to your site. If you have other websites then you can link to your Wordpress blog.
You can also participate in various related niche forums and get some traffic to your blog.
Hope this helped
