New Quay Bay has a lovely long sandy beach as you can see from the photo below. When the tide is out you can walk all the way along the beach into New Quay which is a lovely walk of maybe around a kilometre. Do note though that when the tide comes in you won't be able to reach the town, so its worth checking high tide times if you're aiming to do this. The town itself has 2 nice but fairly small beaches and there is a car park at the sea front.
With reference to the map below, you can park near the beach by driving down the hill, going straight across the main road and carrying on along Cei Bach Road until you get to Llanina Wood Parking. Go slowly as its easy to miss. From the parking area its a short walk across the road, through the woods, down to the beach.
Alternatively you can walk down to the beach. The easiest route is to go down the hill from the property, turn left at the main road and then go right into the Quay West Holiday Park. You can walk through the holiday park and down to the beach.
Somewhat further away you will find Mwnt beach (see picture below) is small but absolutely stunning (https://www.cardigan-bay.com/mwnt-beach-cardigan-bay/). Its a bit off the beaten track - the drive from the house takes about 40 minutes, but it is well worth it on a nice sunny day. There is car parking and a small but decent cafe with toilets.