New Duplex PM questions

[Justin Case]

Hi fellow investors,
I am new to multi family investing. I bought two duplexes last year downtown Seattle.
I just found this forum. Glad I did!
I have a few questions for experienced REIs.

TAX

Can I write off things I bought before purchase?
Examples:
Driving to look at potential props
Buying books etc? Research

What info and in what format do you take it to your accountant?
Leases & Addendums etc?
What if I lost a few receipts? (low priced items) >$100

How is mileage claimed? Gov mileage rate? 55 Cents
What mileage is allowed to be claimed? Ex driving to the the hardware store for supplies? Driving to get mail from PO BOX for property.
How do you track mileage? Put in excel sheet?

What time can you write off? Ex. Mow the lawn etc..

How to track expenses in what application?
Excel, MS Access or Quick books?
What is ideal for 4 units? LLC or Trust? ? What documents do you have to change? Title, insurance , loan etc
How do you set a budget on what to spend per year per unit?
I know $0 is ideal but you have maintenance costs. Like mowing lawn, clean gutters, risk, etc..
How do you figure this when you don’t know the future ROI on the property?

I appreciate any hard knocks info!
-J