How can he move to the US and does he have to marry me in the US or can we get married in Scotland?

Assuming you are a U.S. citizen, there are two primary options for you and your fianc? to consider: you could get married in Scotland (or any other country outside the U.S.) and then proceed with consular processing to seek to authorize your husband to enter the U.S. and become a Lawful Permanent Resident (to get a "Green Card"), or you could petition for him to receive a fianc? visa which would authorize him to enter the U.S. to become married to you within the required time, and then proceed with a marriage-based adjustment of status application (with an application for him to receive an Employment Authorization Document allowing him to be employed while the adjustment of status application remains pending). There are advantages and disadvantages to each option, and the costs (including attorney's fees for legal representation) would depend upon both the choice of process and details not mentioned in your questions. It would be wise for you and your fianc? to consult with an immigration attorney who, after learning all of the relevant information about both you and your fiance, could advise about immigration eligibilities, options and strategies, including advice about costs/fees, time to achieve your goals, and attaining eligibility to work, and who could offer legal representation for the often complex application process.