Hi Betty,
The best place to start is with a Weight Loss Seminar usually provided periodically by the Weight loss Center you choose to go to. There are qualifications before you would even be considered for WLS. ie: BMI of 40 or higher or BMI of 35 with comorbidities such as diabetes, sleep apnea among others. The purpose of WLS is to lose weight, it is the loss of weight that helps the diabetes for example. The surgery by itself won't cure any of the problems. You still have work to do as WLS is only a tool.
Tons of information can be found on the internet. They even have videos of how the different surgeries are done. I haven't met anyone who had bypass surgery (even with complications) who would have done anything different. It's a matter of getting healthy.
It is quite a process with a psych evaluation, nutrition classes, sometimes a multitude of other tests just to get ready for the surgery. Each Center is just a bit different. Insurance is most often a big consideration because not all insurances will pay for WLS.
Good luck on the journey should you decide to go ahead with it.
Joy