In traditional gaming or tactical gaming, close would be two minis touching — intimate, combat range. Near would be about 5 or 6 inches apart, say 30 feet (not close enough to swing swords), and far would be twice that far … 10 to 12 inches … say 60 feet, definitely ranged combat distance. Another way to “scale” it would be close is equal to two minis touching, near is roughly five or six mini bases apart, and far is double that … 10 to 12 mini bases apart.
We don’t get too wrapped up in it. At the table, close might be the pad of your thumb, near is thumb tip to index finger tip spread out, and far is thumb tip to pinky tip spread out wide. Or just use a banana. lol
For your turn, you can choose not to move and take your action, or you can make a near move and take your action (or take your action and then make your near move, or some combination of the two … move a bit, take an action, and then finish your near move), or finally, you could forgo and action and just spend your whole turn making a far move.
Hope that is clear as mud.