Hooklength - 5 foot of 8lb Drennan double strength for me - make sure its the gold labelled floating variety. Be minded that after each fish you might have to replace the line as it can be prone to kinking/damage drastically reducing breaking strain. Use in conjunction smaller korda wide gape hooks.
Beach casting is a great method - lots of views for & against. Can be a little fiddly for those whose not seen this used before, tho the principles straight forward enough. Savage takes too.
Chum mixers a firm favourite but also consider cat biscuits like munchies, lots of different shapes & shades. A bit different & esp good as they all not a standard size. Baits quite small for catapulting more than 20-30 yards so either place freebies in a spod or catapult PVA bag. For preparation of chum mixers, put in maggot box, pour boiling water, instantly drain & cover just prior to leaving home for bankside - slightly softer so easier to hook (side hooking or on hair) & slightly extra mass can get an extra 10 yards with catapult.
Fish with the wind behind you so you can slowly get that bait trail in water - but be mindful that carp on some waters will follow & be located at the end of a new warm wind. Fish will take baits more confidently in choppy waters for obvious reasons. Try & fish just inside the edge of the chop if there is a little flat water where the fish are. If possible, over cast bait beyond fish & very slowly reel bait close to where the fish are feeding.
On a few waters, carp not that keen on biscuits. Bread can be a really good alternative in these circumstances, tho requires a bit more micro management due to little longevity.
Arm oneself with polaroids & a pair of binoculars to see the fish a little closer.
One of the most exciting forms of fishing in my opinion.
Good luck & enjoy
Jon