Advice on entering via New Zealand

I am in my late 30’s and may soon be moving to Boston and am looking to get involved in the merchant seaman industry. I am looking for any advice, tips, warnings, opinions. Anything really that might be beneficial to me as I consider/work towards becoming involved in the industry. So my back story. I am a New Zealander/New Zealand citizen. I have worked as a rancher for many years and also worked as a line cook and as a deck hand on a small charter fishing boat. I am not currently a US citizen/legal to work in the United Sates but am getting married to a women in Boston, hence my need to get involved in a new industry and the Merchant Seaman seems to be a realistic option. Any information at all would be appreciated. Websites, testimonials, individual opinions, realistic options for me, any prep work, study I could do for myself while I’m getting my legal status organized. Anything anyone believes could be beneficial. Thank you.