I drive a car.

unten : driving (noun)
suru : do
untensuru : drive (verb)
kuruma : car

Watashi wa kuruma o unten suru.: I , car , drive : I drive a car.

Sometimes "noun+suru" becomes a verb.

hakken : discovery
hakken suru : discover

The conjugation of "suru" is below;

shinai : do + not
shimasu : do (polite)
suru : do (plain)
suru toki : do+when
sureba : do+if
shiro : do (imperative)

Watashi wa unten shinai : I, drive, not : I don't drive.
Watashi ga unten shimasu : I, drive, do : I drive.

The difference between "wa" and "ga" .

In order to make a noun a verb, " wa " or " ga " is attached to a noun.
Generally "wa" would be attached to a noun and make it a subject.

But "ga" is attached , the subject word is emphasized.

"Watashi ga unten shimasu " means " I drive" , but the nuance is " It's me to drive".

When there are some people and someone should drive a car, you say " I drive a car".
In Japanese, "Watashi ga unten shimasu" is right.

When you are asked " Do you drive a car?", "Watashi wa unten shimasu" is good.

And the difference of "wa" and "ga" is sometimes explained as a difference between " a" and " the " in English.

inu : dog

Are wa inu desu. : that, dog, is : That is a dog.
Are ga inu desu. : that, dog, is : That is the dog.

It can be explained that " ga " specifys the subject.