No "rod" license required in scotland. All fresh water fishing is out of season until the mid February for salmon and sea trout (west coast, but subject to local variation) and 15th March for brown trout.
Sea fishing, would be best from a boat at this time of year although steep (kelp free) banks and sudden drop offs would be bait fishable from the shore, spinning off the rocks, or fly fishing with sinking lines and big streamers off the rocks, would put you in touch with pollock (cuddies, as they're know round these here parts)and possible sea trout, big green cod are in about at this time of the year, up to 30 and 40lb's +, that'll put a bend in your rod, to get at them and be able to land them you'd need to be in a boat.
A hand line and feathers, "darrows" as we call this set up is easily got (in fortwilliam for sure) and low cost, better than a rod from a boat, and that set up will put you in touch with what ever's on the go, other than the semi static bait munchers, conger flat fish dogs etc.
No tackle shops within 50miles of the Ardnamurchan, there's one in fortwilliam, and that's yer whack, unless you find yourself in Oban or Inverness, both are miles away. Most small shops will sell hoods and bits and bobs, darrows, perhaps even a rod or two. But if you want kitted up, best to do it before you arrive.
There's no easy answer to your question, being a novice I'd recommend asking the locals when you get there, darrows work and cost little, sparkly holographic feathers being best
, if you were going down the rod route I'd go for a small to medium spinning/bait rod as that would have other fishing applications.
With the darrows though, you could run the line out at low tide, anchor the weighted end securely and add nylon mono droppers (15lb) at intervals of say 5 to 10 foot, add and bait a hook (size 2) to each, run the line back up to the shore and tie it off, retrieve at low tide. You'd need a sheltered shore and hope that all the local seals have either been shot or eaten by the local orca pod, although if there aren't any signs of seals when you scope out a spot they are unlikely to get wise for one or two attempts, gulls are an issue too but not if the tide is dropping in the dark. "caostalsurvival" on here has a few vids around showing set long lining, so check it out.
Mussels make the best bait, hook on to the tough bit.
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