Hi,
The area around the pond is for day use parking only, as the posted signs so designate.
Everywhere else is first come/ first serve. When I arrive at the WP around 0400 or 0430 during the summer, I will almost always be able to park within 50 to 100 yards of the Trail Head.
However, during daylight hours, do not expect such primo spots to be empty and waiting for your arrival. Then, parking is found in the Overflow Lot below the Walk-In Campground or along the Portal Road. (Beware, sometimes the Overflow Lot completely fills.)
If I plan to sleep (inconspicuously) in my car at the WP before a hike, I will arrive after the Portal Store has closed and many of the hikers have returned to the Trail Head and driven away. Again, in this case a primo parking spot is usually easy to find.
Out of courtesy to others, those in the backcountry for extended periods sometimes consider parking in the Overflow Lot or along the road.
Hope this helps.
Jim F