You can go sea fishing anywhere really, you don’t need a rod licence and it is nearly all free fishing if done off the shore line, some clubs run contests for beach fishing so you might need to find out if there is one on but very few of the coastlines are private so you can fish almost anywhere you like but always check the local bylaws, these do differ from one area to another but over all you can sea fish without licence anywhere but if it is your first time get some help because there are many dangers involved and never go alone, take care with tides because these turn quickly and can catch you out…in a nut shell just find a beach or cove and ask the locals about the fishing, they should know but of course you can go out to sea on a charted boat if you can afford it, the options are there…good luck.
You can go Sea Fishing any where along the coast line, from sandy beaches, shingle beaches, harbours, pier, breakwaters, marinas, cliffs, rocks. Some places are private or you might have to pay to fish from them, pier, harbours, breakwaters, marinas, bridges etc, some are out of bounds MOD land, some cliff or rocks are just too dangerous to fish from, even some beaches, mud flaps, sand banks and coves you can get caught out with the incoming tides, even shingle beaches at high water, the sea will wash the shingle from under your feet. Always set up your base, above the high water line, this is where the weed and rubbish lies on the beaches from previous high water, just think safe in your safety and others, tell people where you are fishing from and how long, if change the place then tell people. You can always walk to the water edge to cast, just be careful of the waves. Even from the safe rock or cliff face a rising rouge wave can knock you off your feet and into the sea or you can easy slip on wet sea weed on rocks, just be aware of the dangers and keep safe.