lyon, I don't know which part of the armed forces you were in but if you were lucky you may have already covered most of the basic syllabus when in.
Ray Mears is a full time civilian. Its refreshing when coming from the militarty as dealing with civilians is different in a whole lot of ways
Ray Mears has been into survival forever, is up to date, and travelled widely.
The Ray Mear courses should be good but I think you need to decide what you actually want from a course as they differ. Some people have never slept under the stars which to them is wild
You might just need some practical help with identifying edible plants.
There is a huge source of written material, stuff on the net and some videos which you can gain quite a bit from. However, the best way of learning is getting out there, back garden will do, and trying it for yourself. Trial and error until you find your way to make it work. Survival is all to do with keeping an open mind and making do. Its fun anyway.
Tracking takes quite a nack. You really need to know your ground and the habits of what you are tracking well. There is nothing secret in how to do it as its all to do with "reading" the signs. That takes experience and practice which takes time and aplication.
Lastly you don't have to buy much kit or you will end up camping.
Even a St Johns Ambulance first aid course is worth while.
