Rather than focusing on credentials at this point, you should get some practical experience working with a good mentor with strong technical skills (beyond being to read and understand a Pub) so that you could learn the ropes of the trade.

You will learn a lot from the review notes you [should] receive, if you pay attention to them, and understanding the statutes, regulations, and case law is what will enable you to stand on your own two feet over time.

While you're at it, devote a couple hours each day over a number of months to prepare for whatever exam you plan to take to earn the credential of your choice.

There's no minimum qualification per se.  Anyone can be a preparer.  But if you're not an attorney, CPA, enrolled agent, enrolled retirement plan agent, or enrolled actuary, your rights to practice and represent will be limited.  You can read more about this here: https://www.irs.gov/publications/p947#en_US_201709_publink1000148603

Whatever credential you decide to pursue, this is a good resource for learning taxes: https://www.gleim.com/enrolled-agent-review/