If so what kind of training they would have to go through ? By training I mean the spatial and situational awareness, combat skills (this is kinda unrealistic), enough knowledge to turn any situation to their advantage etc.
Just think of the person as your average joe who financially has nothing to spend on high tech gadgets or state of the art training equipment. And doesn't even have any support from another human being. Basically one has to train from the ground up alone.
Don't limit the answers to just James Bond and John wick, you can even consider any realistically possible superhero or supervillain (like batman or taskmaster) as well.