eSim and Charge

1. Can I port my home phone number to AT&T prepaid using eSIM?  Basically, I will have one iPhone with 2 numbers.

Yes, if your home phone number is eligible to be ported.

2. If the answer in question is Yes, I will be charged whatever number I make/answer a call or it will charge to the primary number?

Since you are prepaid, each line will have its own plan, so you will be charged on whatever number makes the call.

3.  Can these 2 phone numbers be managed by one account?

Sort of. Since you are prepaid, each line would have its own plan and account but you can pay for both plans from one account by making that account a multiline account. Something else to consider, though, rather than porting that home phone to another cellular line, port it to google voice. You will still be able to use it as a second line but you won’t pay a monthly fee. You pay a one time charge to port your number to google voice but after that, google voice is free. Calls to/from the google voice number would use your cellular data.