Random topic, visa help please! 🙆🏼

I don't know where to begin but I've been longing for awhile now to live in the UK, in Yorkshire to be exact. My boyfriend and I have been together for four years and I honestly would love to live with him really soon. The fact he's a British citizen obviously allows him to permanently live legally, as I am a American citizen and need all the requirements in order to live there legally, too. I'm so baffled as to what I need visa wise and the requirements to work and reside there permanently. I would absolutely appreciate it if someone helps me out. 😊