Hooks are sized in a traditional and confusing manner. The larger the number the smaller the hook up to size 1, then /0 is added to the number and the bigger the number the bigger the hook, confused yet ?
The smallest hook you will need is a size 4, sizes then go up to size 3 size 2 and size1, then 1/0, 2/0, 3/0 4/0 and so on. The numbers go on up for hooks to hang on to congers and sharks but a selection from size 4 to 2/0 should suit most types of beach fishing.
There are also many patterns of hook, the most common is the Aberdeen hook which is a good all-rounder although the Nordic Bend hook is perhaps finer wire and sharper. Most of my species hunting fishing is done with size 4 or 2 Nordic Bend hooks.
Use fine wire hooks for targeting small stuff, they tend to be sharper and are plenty strong enough to hold most big fish you come across. Do not use stainless steel hooks, if you cannot remove the hook quickly and easily from a fish that is to be returned, just snip off the hook. The normal fine wire hook will quickly rust away in salt water and little permanent harm is done to the fish. Stainless steel hooks will not rust away. Use small long-nosed pliers or forceps to grip the shank of the hook to remove it.
Keep hooks dry and replace if the hook has been blunted by being caught on stones or rocks. Practice tying hooks and testing how strong the knot is before trusting your early tying practise to a big fish that will get away if you have got it wrong. There is a link to a page that teaches knot tying on the right under 'good sites' and here.
Getting a hook in yourself is painful, take care, if the hook is in deep it will mean a trip to the local casualty department. Do not leave hooks or line lying about, they can cause all sorts of problems with small children and other wild creatures.