Can I use an alias when conducting business and interviews?

Using an alias is common when blogs, articles, etc. However, entering into contracts is a different matter. Then you need to use your real name. Registering with the government implies filing a dba statement. That could work since the purpose is to provide public notification of who someone is really dealing with.

If you want a commercial fictitious name you need to file a fictitious business name statement in the county of your principal place of business. Using an alias is permitted but when the public or individual finds out that your are using an alias, your credabliity will be non-existant. You cannot use an alias for contracts to defeat the contract. There is no state registry of aliases.

Lots of writers use "pseudonyms" or pen names for their writing, and there's nothing wrong with that. You can also register your writing for a copyright under your pen name. But as my colleague notes, entering into a contract will very likely require your real, legal name, if that's how you do business. You should see your own iP lawyer so you can properly organize your business and IP assets.