@Pianostrings
There's free parking at Seaford beach and lots of it. For the walk, it's a clifftop walk and there will be others doing it that you can basically follow. You literally go to the far end of the beach (the left end) and you can see where the path starts/ ascends. You can't get lost. It's hilly but stunning. If you ever get stuck with walks, there are lots of websites online which will tell you good local routes with lots of clear directions. That's what i do! They tell you the length of the walk and the difficulty.
Have fun. It's a lovely area. I grew up there.
..but stay WELL away from the edge.
The underlying chalk is more like a sponge than something solid and is full of rabbit holes and water erosion channels. If you stamp your foot on the grass, you'll feel and hear how hollow it is. Just don't do it near the edge.
If you want to sit down, watch out for Viper's Bugloss. It's a beautiful plant and amazing for wildlife, but in areas that are heavily grazed, it grows low and almost invisible until you sit on it.
Keep an eye out for the butterflies. Just a little way over from the actual main walk, you'll see the field full of blue and brown butterflies dancing at about knee level. They're the males and females of the Common Blue and it's the most amazing sight.
In fact, spend at least some of your time looking down. You'll see a massive amount of things that you won't notice if you're looking out to sea.
If it's safe, at the base of the rocks to a short distance up, it's not unusual to see fossils of bivalves, sponges, ferns and other creatures (bits of fish, for example) and find natural quartz and silica crystals amongst the flint. but follow whatever the safety instructions are, as depending on the stability of the area, it can be safer to stay well away from them and look around the rocks on the shore rather than further back.