Go ahead.
Wordpress is the great platform for hosting website/blog.
I'd recommend
hostgator to host your blog. They are very reliable and you may install Wordpress and start blogging within 2 minutes.
Having self-growth related words within domain name helps to get ranked but not required if you are dedicated.
I'd suggest to go with brand-ish looking domain name instead of keywordish, like - my-self-growth-and-self-help-blog.com
Gleb