If I contributed all of my stimulus money into my HSA, do I report that as personal contributions to my HSA for 2020 since it did not come from my taxable income?

they are independent transactions

1) you received stimulus money that was not taxable,

2) you put money into your HSA that has the effect of reducing your taxable income

it may be you took the money from #1 and deposited it into #2, but the IRS wouldn't look at it that way.  Just follow the TT interview prompts and you'll do fine.