You just bought a car with rims but the lug nuts are round with notches how do you get the wheel off?

That is called A antitheft nut. You should have A tool in the car for it, It will likely be in the trunk near the spare tire or in the glove compartment, It will look similar in size to a lugnut and it will fit A tire tool on one end and be the reverse ov the lugnut on the other. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,, If your tool is lost, Go to A dealership, They will remove them for about $20 each.