Welcome, no need to be embarrassed about your weight. You need to know where you're at before you can start. Here is an excellent BMI calculator that will tell you where you're at and what you need to do to get to your goal weight.
Some other tools to help you along would be myfitnesspal, a free and easy app that you can use with smart phones, computers, etc. that helps you keep track of the calories you're consuming during the day. You can also add sync other devices and apps to track how many steps you take in a day-like Fitbit and Jawbone Up. It's amazing what it does.
Take care--and good luck on this journey.