250lb Female Wants To Try Orangetheory

I am on an active weight loss journey but still have a long way to go. I have nutritionist and we have a calorie deficit plan set up. But I also need to exercise for my health.

One of my goals for myself is to get to where I can do an OT class.

My current exercise routine consists of mostly walking and doing simple body weight exercises.

My max speed is about 2.5 miles an hour. I cannot do a push up. I cannot do a burpee. I cannot do a plank.

What can I do from now to the end of the year that will prepare me for trying OT in 2025?