Extremely obese (380 pounds) trying to make a change

Hey everyone, I'm new here, actually brought here as a suggestion from my doctor. As the titles says, I'm extremely overweight from a mix of overeating and simply not being active for a large portion of my life. My actual diet could use work too but is definitely less of an issue currently than the lack of moving and amount.

I gotta admit, I'm lost here. I don't know anything about excercise or how to do it properly/safely. Especially at my weight, I worry about overdoing it and giving myself a heart attack but I know I need too (and want too) make a change and start losing weight. Building muscle would be nice too, but if needed that can easily be secondary, i simply want to be healthy.

Any guidance would be deeply appreciated, especially on what types of workouts I should be looking into as well as what kind of schedule I should try and set up. I'm not sure how it is for most people, but having things scheduled and planned out ahead makes things easier for me so future planning is definitely something I want to get down.

Currently a free user, but I don't mind paying monthly if it opens up useful options, I just don't want to pay right this second when I don't even know what I should be looking to do. Thanks in advance for any and all advice, from what few threads I've ready, this community seems extremely helpful, so again: Thank you.