Here are some guidelines:
Don't rape anyone, especially old/mentally incapacitated people.
Don't have sex of any kind with blood relatives, even if you think they really want it.
Don't troon out, even if doctors say it is heckin valid. It isn't.
Follow these simple guidelines, and you will come out ahead regardless of what else you do.
To improve on that baseline, start lifting, even if it is pathetic at the start. Exercise is about consistency. Keep at it and you will improve. Buy weights/do bodyweight exercises to start. Gyms aren't worth it unless you are willing/able to commit to them regularly, and membership agreements tend to be expensive/hard to get out of. Learn to cook, and cook healthy food. Your tugboat will go farther and between eating healthy and exercising, you will feel better in general. Get a job. Part time cashier job is probably best start. If the income would fuck with your tugboat, volunteer at a charity or something like that. Important thing is you start talking to people irl on a semi-regular basis and learn how to interact with normal people. The structured nature of the interactions will make it easier and get you used to interacting with other people.