Hi lynntina
Weight gain is very common leading up to menopause and beyond - our metabolism slows and muscle strength decreases. Also decrease in oestrogen and relative imbalance between oestrogen and testosterone (which also decreases) alters weight distribution so we change from pear to apple shaped with more fat around our middle ( and internal organs I gather).
Therefore most women need to change their diet (what they eat), eat less and exercise more just to stay the same weight.
Provided you don't have any other health issues ( eg thyroid) or taking medication that can lead to weight gain, then you should be able to lose it if you put your mind to it. I did. Cut out all sugar (not counting fruit), and refined/processed foods. Limit carbs especially refined carbs and have at least one meal a day with no added pure carbs ( ie bread, pasta, rice, potatoes, cereal, pastries, cakes etc), no sugary drinks, limit juice and alcohol ( latter at weekends). Eat more lean protein especially fish, and heaps of fruit and veg, as well as nuts and pulses, yogurt etc. Do lots of walking, plus some cardio work-outs to keep your heart healthy and some weight resistance to strengthen your muscles. If you replace fat with muscle it burns more energy at rest and therefore you can eat more ( or lose weight more easily!).
As Megamind says - some women like to go to a class, whereas others like my daughter have a WW app on their phone and track it all like that. Me - I've never got on with counting calories and limiting how much I eat in that way so I've done it by portion sizes and eating tons of stuff that is low calorie if necessary as I don't like being hungry.
Hope that helps and good luck!
Hurdity x