Nancy, you can see pictures of the beach and the trail to the east end of it at hawaiiweb.com/kauai/html/beaches/lumahai_beach.html

The east end is the most-photographed part, where you see the black rocks in the water. The shortest route to that part is the trail from the pullout on the highway. The pullout is not marked and there is I think room for 2 or 3 cars. I've been to the east end once many years ago , and on subsequent trips have not been able to find the pullout. But as we've always been on the way to other beaches, haven't tried too hard. The trail is a bit of a scramble as I recall. You can also access the west end from a larger parking area. But it is almost a mile from one end to the other and walking in the sand might be difficult if you are trying to keep your clothes clean.

The hawaiiweb site has pictures of other beaches as well.

I think you posted elsewhere that you were thinking of staying at Hanalei Colony Resort. About a half mile east of HCR the beach ends at a small cliff. and you get that effect of the surf breaking on the black rock. It's near the road and there is a house there, but seldom any people on the beach. You could either stand on the beach or walk out on the rock (depending on surf and weather conditions).