Ka Hung Chan

I have contacted HRMC Self Assessment several times, but advisors of HRMC hotline cannot provide advice for solving my case. I don't know how to register and obtain an UTR Number because I am new to UK from Hong Kong. I am retired with interest income only. When I go through SA1 form, there's no box for me to indicate interest income if I am registered as 'not employed'. What can I do for register an account for self assessment and obtain my UTR numbers? Any advise.