I have a rental property and I'm I'm entering actual expenses for it.

How to I calculate Gasoline and Vehicle Insurance?

Say I use the car 1 time every 2 weeks to go to the property.

For Insurance - should I enter the full cost of Insurance or only the number of days in the year I used it for traveling to and from the rental?

What about Gas?

If I traveled 10,000 miles in the year and 1,000 was for rental property.

If I spent $1,000 on gas would I enter $100 for Gasoline in Turbo Tax or the full $1,000

The key is to calculate the % you use your vehicle for Business.

If you calculated that you used your vehicle 10% for Business (as in your example), then 10% of your Actual Expenses can be Vehicle Expenses for your rental.

However, when you enter your Personal/Business miles in TurboTax, the program calculates your Business Use % for you, and you only need to enter annual amounts for items like gas, oil, tires, etc. 

Some different rules apply if you use your vehicle less than 50% for business, though you can still claim expenses.

TurboTax gives you the Standard Mileage deduction amount first, then you can choose to see if Actual Expenses gives you a larger deduction. 

Click this link for more info on Using a Vehicle for Business.