The property was sold to the investor/rehabber since I have been tracking it several months ago.

Do they issue 1099 to you or you track your income and file tax return?

(Every birddog that works for us has a separate number so we can track the leads/deals and pay them accordingly)Thoughts?

Your on the right track having gone and toured the city for yourself before jumping in.

Does the LLC have to already have previous credit history and a proven track record or can it be completely new?

This would be a minimum if you want your spreadsheet to match your experience.We tracked our clients for some years on over a hundred rentals and generally they achieved 78% of what their spreadsheets said they should.   

CallRail to track calls and which list they come from.

I think you are on the right track.

Here is another one to check out for tracking all your expenses.https://www.biggerpockets.com/files/user/JimA732/file/rental-expenses-report

From a fire at a nearby property and resulting damaage to The Shelby", to delays in fire damage repairs due to Covid 19 restrictions, to renters not paying rent due to Covid 19, to an approx. 20% vacancy rate, to insufficient reserve funds, to an obvious lack business loss insurance - Passco continues to underperformance on every statement they made at their seminar - from the safety of the investment based on their previous track record, to the expected annual distrubution amounts paid out.