I'm a CPT.

Ditch Optavia. It's a terrible MLM and isn't sustainable or healthy and it teaches you nothing about nutrition or how to eat for any kind of goals. If you have significant weight loss needs, or medical issues to consider, start with your doctor and get referred to a Dietitian to get started. A nutrition coach is also an option and they can work with your providers to help you lose weight safely.

As for the exercise, You have options for getting started. You have great access to equipment with those gyms so you could get a trainer to design a program for you that you can do yourself. You can find trainers through the gyms I'm sure. Trainers are a great tool because they offer proper programming, progression, accountability, and instruction. And a good trainer will adjust your program based on your feedback.

I recommend at least meeting with a trainer and getting something custom designed for you personally instead of just trying to follow a generic one you find online. This will help you avoid getting hurt and address your actual goals. It will cost a little bit to buy this but it's a cheaper option.

You could work with an independent trainer and nutrition coach, like myself, that doesn't operate in a gym. This avoids the gym anxiety and is a great way to get started. There's often more flexibility with this on location and scheduling. Trainers aren't cheap, but there's usually no long term contract and cancelling service is way easier than trying to get out of something like a Gold's Gym membership.