Well, first thing to do is to work out if you can qualify for a visa to move to the UK.
What's your current personal situation... Do you have any claim to UK or EU citizenship? Are you married to a UK citizen? Do you have skills that could transfer to a UK job? Do you want to go to school in the UK?
Your options basically are:
1)
Sponsored work visa with a UK company - can be very difficult to get unless you work in a very specialised, highly-skilled field or in an occupation that is in shortage in the UK. There's a list here of the jobs that are in shortage:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/308513/shortageoccupationlistapril14.pdf. If you don't work in one of those jobs, then the UK company has to prove that there is not a single person in the UK or EU (that's 500 million people) who can do the job before they are allowed to hire you. See here for more info on the visa:
https://www.gov.uk/tier-2-general/overview2)
Sponsored Intra-Company Transfer work visa - if you work for a US company that has branches in the UK, you might qualify for a transfer visa to a UK office. See here:
https://www.gov.uk/tier-2-intracompany-transfer-worker-visa/overview3)
Student visa - you can apply to study for a university degree in the UK. Relatively easy visa to get, but you need a lot of money available to you (personal accounts or loans) to qualify for it. See here:
https://www.gov.uk/tier-4-general-visa/overview4)
Marriage to a UK citizen - if you are in a relationship with/married to a UK citizen, you might be able to qualify for a spousal/family visa (although there is an income requirement for the UK citizen). See here:
https://www.gov.uk/join-family-in-uk/overview5)
Marriage to an EU citizen living in the UK - if you are the family member of an EU citizen living in the UK, you can live and work in the UK with them. See here:
https://www.gov.uk/family-permit
