If you make a blog on tumblr, your da would be 97 or something. But you're seeing it all wrong. That's domain authority doesn't have much to contribute to the actual quality of your blog. Not saying it's not important at all but having a good DA doesn't guarantee better rankings on the search engine. Infact, DA and PA are almost useless these days. Always check for Majestic TF as it has always proved to be more accurate.
Also, where ever you create your first blog, your TF would be shown as NA. It will increase as you start to create HQ backlinks. In short, where ever you decide to create your first blog, the important part is to correctly promote that blog or else all these metrics are useless
