You can’t. :c
I can’t? but how did you follow those blogs I see on postcrude?
I have my primary blog (the first one) set as postcrusade so I can follow people or ask them questions and they know what blog I own.
The actual PC is on post-crusade (note the dash). It’s a side blog.
You can’t follow other blogs as your side blog. Only as your primary. The same rules apply to sending questions and submissions. And you can’t make a side blog a primary. That’s just how Tumblr works.