What is the best phone number to call to speak with a human being?

Phone support is not provided with the Free Edition.  If you are using a paid version of the software or if you purchased PLUS you can get phone support when customer support is there Monday-- Friday 8 a.m. to 5 p.m. Pacific time.    Otherwise, post your question here and someone will try to help.

To call TurboTax customer support

https://ttlc.intuit.com/turbotax-support/en-us/help-article/account-management/contact-turbotax/L2y9ZKpQB_US_en_US?uid=m5s9l2vh