i will be traveling to the usa and will pick up a rental car on arrival, on the immigration form i 94?

must i have a address or can i put eg. touring in the mid west? will i be refused entry if i do not state where i will be staying.?. i refer to immigration form i94.

One of the requirements to entering the United States is that you must have a place to stay for your first night and once you arrive at customs and immigration you may be asked to provide proof of this; a receipt of payment if you booked online is perfectly fine.

"Touring the mid-west" is not acceptable and there is a good chance you will be refused entry if you write this.

So yes, on the I-94 you will have to put the actual place (number and street) of the place where you are spending your first night.

So basically work out which state and city you are going to be spending your first night in and book a hotel, motel or hostel room in that location, print out the receipt, fill in the I-94 appropriately and you will be fine.