When you lift a frame out hold it horizontally over the hive. Slightly tip it back wards and read it from top to bottom like a book. then lower your left hand, so that the frame is vertical with the bottom facing the right. Now turn it gently so that the bottom is facing to the left and lift you left hand again. The frame is now upside down but you are looking at the other side. Tip it back again slightly Once again read it like a book from top to bottom. Your eye will rest on unusual bees, usually drones, but with luck one will be a queen. Don't try and study every bee you will be there for years!. Now ... this is the important part, turn the frame again just like you did the first time but this time immediately look round the edges and at any holes in the wax. the queen will always try to go to the dark side so this last twist will catch her out!
Do this with every frame. The chances are she won't be on a frame with food, the chances are she will be on a center frame with eggs the chances are she will be on a noticeably quieter frame than most.
Try and look for her when bees are out flying, I find between 10 and 11 am good on a warm day as the first batch of foragers will have left!
If you want to reduce the bees even more then move the brood to a different location while you look for her so that flying bees don't return but I don't advise this for a newbee.
You will find that over the years you nearly always see her by accident, your eye gets trained to spot the unusual. Finally when you find her marke her with eco white tipex. It has a soft pad end, drys quickly, is water based and lasts as long as the queen. As a newbee don't worry too much about colours, blue can be hard to spot even at the best of times! Luckily this years is white anyway.
Good luck
E