Take it one step at a time.
There are lots of resources on SP to help you along the way and many great people to encourage you.
Have fun at the gym. Don't let your concern about what others will think distract you from what you know you want and need to do.
Your goal is very reasonable and achievable. The only caution i might add is to plan to lose "an average: of one pound a week. When I started this journey I wanted to lose all the necessary weight sooner rather than later. My friend encouraged me to think of average weight loss instead of pounds per week and it really helped me stay focused and encouraged. Weeks I didn't lose we would talk about non-scale victories...clothes fitting better, having less trouble breathing when exercising, blood sugar being in normal range etc....
Enjoy the journey to a healthier you!