Once you realise you are not sure where you are, there are a few steps to go through. The first thing is to STOP where you are. No good walking on aimlessly.
1) Look around for features. Look around you to see if there are features that you will probably be able to see on the map. Are you on a path? What is close to you, what is in the middle distance, and what can you see in the far distance?
2) Where were you when you last knew where you were? How long ago was that? What direction have you been walking in since then? How far might you have walked in during that time? What have you passed since and when?
3) Put all that together with what you can see on the map. It is a good idea to start with your last known position/location and work forwards following your route recalling what you passed. All being well, you should be able to identify your position with ease using the features you identified in step 1.
Pay particular attention to scale. What if that doesn’t work? If you are getting nowhere, you may wish to consider one of the following courses of action
1) Move around a bit to see if you can see more helpful features. Don’t go far but moving a short distance will often reveal new features. Move to higher ground for better sight of features.
2) Backtracking to a place where you knew where you were. Learning how to relocate is more about looking around you rather than looking at the map. When lost, inexperienced navigators tend to start studying the map intently looking for clues.