If you qualify for split year then you only report any foreign income for the UK part of the year. You can see guidance here:
RDRM12000 - Residence: The SRT: Split year treatment
If you do not qualify then you will need to report all your foreign income to the UK. You can see information here:
Tax on foreign income
The following guidance will help you work out if split year treatment applies.
RDRM12150 - Residence: The SRT: Split year treatment: Case 4: Starting to have a home in the UK only