Right first 'essential' is a recovery buddy.... NEVER go laning alone, take two or more vehicles, and try and as a newbie, try and buddy-up with some-one with a bit of experience AND nouse.
As for 'kit', to be honest for the stuff you ought to be sticking top as a newbie, you can 'get away' with nothing more than a cheap petrol station two rope (or two), on the standard towing eyes and a spade or shovel borrowed out the garden shed.
your recovery Bud, if they are more experienced should have a bit more heavy duty kit to hand if they've been at it a while, if needs be.
Common sense and a little injinuity though are the MOST useful things to pack........
as for going and buying the 'goodies', depends on available funds, but top of the list, I put a CB.....
Recovery kit is there 'in case' while a CB is something you can get a lot more use from straight away. Its a good laught, being able to have a bit of banter with your fellow drivers, but also a big confidence boost if the lead driver can warn you of whats coming up, and talk you through tricker sections, or just keep you 'in touch' with whats going on, when the convoy halts or gets split up, or whatever.
After that, PROPPER recovery rope, around £25, is the next essential, and Jate Rings or recovery eyes on the front to hook it up, while at the back the jaw and pin tow hitch on a conventional tow bar is the most common recovery point, though some go for Jate Rings through the chassis as the tow bar can rob departure clerance.
My advice for a newbie though is to go for a tow bar and jaw, though, as the tow bar banging on the floor gives you some early warning of when you are reaching the limits!
After that theres all manner of 'stuff' you can go for, but a dedicated compact folding shovel is more conveniently carried than a garden spade; loppers and saws can be useful on severely overgrown trails, but again, can be borrowed from the garden shed.
Kenetic recovery ropes, bridles strops, bridging ladders, all that kind of stuff is really stuff to start thinking about only when you have encountered situations that demand it, and when you've got some kind of experience and idea of what and how often you are likely to encounter stuff on the trails you are most likely to drive.
Last advice then is on Tyres, and on that topic, for a newbie, I always reccomend a decent All Terrain.
Muds are great, but they will get drag you a long way into trouble before you realise it.
AT's not being so capable, will give slip a lot sooner and help you learn when traction is lost and how to drive for traction, without getting too into seriousely into trouble in the process, and as such are a great training tool.
Other 'kit' to consider if funds allow, for a newbie, simply becouse you are more likely to cock stuff up, is under body protection, such as steering guard (typically around £80) or diff guards (normally £15 an axle), but aren't essential, I've not had them on any of my Landies in ten years and all I've managed to ding in that time has been a £15 steering damper!