Here are a couple of resources for you:
What are Federal Taxes? https://turbotax.intuit.com/tax-tips/general/what-are-federal-taxes/L4M1hVs8j
A great list of articles on general tax subjects can be found here (please scroll down the page for a list of articles that you might find helpful): https://turbotax.intuit.com/tax-tips/general/
**Mark the post that answers your question by clicking on "Mark as Best Answer"
Thee IRS has a course in tax preparation on line https://www.linklearncertification.com/d/
The tax prep services run courses to train new workers for free.
This might be of intensest to you
This might be of interest to you https://www.jct.gov/CMSPages/GetFile.aspx?guid=72cd3d31-f681-4bff-80e6-1dd04c009d9d