By default, Google will continue to indefinitely retain the Web & Activity data you've set it to collect—everything by default. In this state, before auto-delete is turned on, the Web & App Activity page says, “Your activity is being kept until you delete it manually.”
If you drive, walk, or park on your new concrete any sooner than the recommended time, here's what may happen: It may crack. You may leave tire tracks or footprints in the concrete, which could also ruin your shoes. You might weaken the future strength of the concrete.
Your concrete should be solid enough to walk on, without leaving footprints, after anything from 24 to 48 hours. By seven days, your concrete should be cured to at least 70 percent of its full strength.