Here is a good link that can help you out on becoming a non- credentialed tax preparer. Right now the IRS does not regulate tax preparers, however there is a bill trying to pass in the government that would require tax preparers to meet certain minimum qualifications. 

They leave the states to regulate tax preparers. So depending on your state would determine how much work you would have to do.

 However without being a CPA or EA you can not represent your clients in any dispute with IRS. That means that many clients will want to go with someone who is certified as they have no protection under non-credentialed preparers. 

You can also work for a CPA or under them and be able to prep taxes however most of them require you to have at least a BS in accounting. If you find a mentor that would help as a lot goes into taxes and many laws; after taking classes on taxes, preparing individual taxes  and getting my BS I realized how little I actually knew about taxes when I started working for a CPA firm. This industry you will constantly have to learn and spend time on education no matter how long you been in the business. 

https://www.microsoft.com/en-us/microsoft-365/growth-center/resources/how-to-become-a-tax-preparer